Delete the redundant word 'to'.
Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20220602180228.4259-1-wangxiang@cdjrlc.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The struct user_ctx *user pointer passed to restore_za_context() is not
a user point but a structure containing several __user pointers. Remove
the __user annotation.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Fixes: 39782210 ("arm64/sme: Implement ZA signal handling")
Reported-by: kernel test robot <lkp@intel.com>
Cc: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220601171338.2143625-1-catalin.marinas@arm.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

After commit e999995c ("ftrace: cleanup ftrace_graph_caller enable
and disable") merged into the linux-next tree, the kernel test robot
(lkp@intel.com) has send out report that there are increased missing-prototypes
warnings caused by that commit.

COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-11.3.0 make.cross W=1 \
	O=build_dir ARCH=sh SHELL=/bin/bash kernel/trace/
warning: no previous prototype for 'ftrace_enable_ftrace_graph_caller' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_disable_ftrace_graph_caller' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_return_to_handler' [-Wmissing-prototypes]
warning: no previous prototype for 'ftrace_graph_sleep_time_control' [-Wmissing-prototypes]

BTW there are so many missing-prototypes warnings if build kernel with "W=1".

The increased warnings for 'ftrace_[enable,disable]_ftrace_graph_caller'
is caused by CONFIG_FUNCTION_GRAPH_TRACER && !CONFIG_DYNAMIC_FTRACE,
so the declarations in <linux/ftrace.h> can't be seen in fgraph.c.

And this warning can't reproduce on x86_64 since x86_64 select
HAVE_FUNCTION_GRAPH_TRACER only when DYNAMIC_FTRACE, so fgraph.c will
always see the declarations in <linux/ftrace.h>.

This patch fix the increased warnings by put the definitions in
CONFIG_DYNAMIC_FTRACE although there are no real problems exist.
Signed-off-by: Chengming Zhou <zhouchengming@bytedance.com>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lore.kernel.org/r/20220506032737.23375-1-zhouchengming@bytedance.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

* for-next/esr-elx-64-bit:
  : Treat ESR_ELx as a 64-bit register.
  KVM: arm64: uapi: Add kvm_debug_exit_arch.hsr_high
  KVM: arm64: Treat ESR_EL2 as a 64-bit register
  arm64: Treat ESR_ELx as a 64-bit register
  arm64: compat: Do not treat syscall number as ESR_ELx for a bad syscall
  arm64: Make ESR_ELx_xVC_IMM_MASK compatible with assembly

* for-next/kselftest: (32 commits)
  : arm64 kselftest updates.
  kselftest/arm64: Explicitly build no BTI tests with BTI disabled
  kselftest/arm64: bti: force static linking
  selftests/arm64: Use switch statements in mte_common_util.c
  selftests/arm64: Remove casts to/from void in check_tags_inclusion
  selftests/arm64: Check failures to set tags in check_tags_inclusion
  selftests/arm64: Allow zero tags in mte_switch_mode()
  selftests/arm64: Log errors in verify_mte_pointer_validity()
  kselftest/arm64: Fix ABI header directory location
  selftests/arm64: Fix O= builds for the floating point tests
  selftests/arm64: Clean the fp helper libraries
  selftests/arm64: Define top_srcdir for the fp tests
  selftests/arm64: Use TEST_GEN_PROGS_EXTENDED in the FP Makefile
  kselftest/arm64: fix array_size.cocci warning
  selftests/arm64: Add a testcase for handling of ZA on clone()
  kselftest/arm64: Add SME support to syscall ABI test
  kselftest/arm64: Add coverage for the ZA ptrace interface
  kselftest/arm64: Add streaming SVE to SVE ptrace tests
  kselftest/arm64: signal: Add SME signal handling tests
  kselftest/arm64: Add stress test for SME ZA context switching
  kselftest/arm64: signal: Handle ZA signal context in core code
  ...

* for-next/sysreg-gen: (32 commits)
  : Automatic system register definition generation.
  arm64/sysreg: Generate definitions for FAR_ELx
  arm64/sysreg: Generate definitions for DACR32_EL2
  arm64/sysreg: Generate definitions for CSSELR_EL1
  arm64/sysreg: Generate definitions for CPACR_ELx
  arm64/sysreg: Generate definitions for CONTEXTIDR_ELx
  arm64/sysreg: Generate definitions for CLIDR_EL1
  arm64/sve: Generate ZCR definitions
  arm64/sme: Generate defintions for SVCR
  arm64/sme: Generate SMPRI_EL1 definitions
  arm64/sme: Automatically generate SMPRIMAP_EL2 definitions
  arm64/sme: Automatically generate SMIDR_EL1 defines
  arm64/sme: Automatically generate defines for SMCR
  arm64/sysreg: Support generation of RAZ fields
  arm64/sme: Remove _EL0 from name of SVCR - FIXME sysreg.h
  arm64/sme: Standardise bitfield names for SVCR
  arm64/sme: Drop SYS_ from SMIDR_EL1 defines
  arm64/fp: Rename SVE and SME LEN field name to _WIDTH
  arm64/fp: Make SVE and SME length register definition match architecture
  arm64/sysreg: fix odd line spacing
  arm64/sysreg: improve comment for regs without fields
  ...

Merge branches 'for-next/sme', 'for-next/stacktrace', 'for-next/fault-in-subpage', 'for-next/misc', 'for-next/ftrace' and 'for-next/crashkernel', remote-tracking branch 'arm64/for-next/perf' into for-next/core

* arm64/for-next/perf:
  perf/arm-cmn: Decode CAL devices properly in debugfs
  perf/arm-cmn: Fix filter_sel lookup
  perf/marvell_cn10k: Fix tad_pmu_event_init() to check pmu type first
  drivers/perf: hisi: Add Support for CPA PMU
  drivers/perf: hisi: Associate PMUs in SICL with CPUs online
  drivers/perf: arm_spe: Expose saturating counter to 16-bit
  perf/arm-cmn: Add CMN-700 support
  perf/arm-cmn: Refactor occupancy filter selector
  perf/arm-cmn: Add CMN-650 support
  dt-bindings: perf: arm-cmn: Add CMN-650 and CMN-700
  perf: check return value of armpmu_request_irq()
  perf: RISC-V: Remove non-kernel-doc ** comments

* for-next/sme: (30 commits)
  : Scalable Matrix Extensions support.
  arm64/sve: Move sve_free() into SVE code section
  arm64/sve: Make kernel FPU protection RT friendly
  arm64/sve: Delay freeing memory in fpsimd_flush_thread()
  arm64/sme: More sensibly define the size for the ZA register set
  arm64/sme: Fix NULL check after kzalloc
  arm64/sme: Add ID_AA64SMFR0_EL1 to __read_sysreg_by_encoding()
  arm64/sme: Provide Kconfig for SME
  KVM: arm64: Handle SME host state when running guests
  KVM: arm64: Trap SME usage in guest
  KVM: arm64: Hide SME system registers from guests
  arm64/sme: Save and restore streaming mode over EFI runtime calls
  arm64/sme: Disable streaming mode and ZA when flushing CPU state
  arm64/sme: Add ptrace support for ZA
  arm64/sme: Implement ptrace support for streaming mode SVE registers
  arm64/sme: Implement ZA signal handling
  arm64/sme: Implement streaming SVE signal handling
  arm64/sme: Disable ZA and streaming mode when handling signals
  arm64/sme: Implement traps and syscall handling for SME
  arm64/sme: Implement ZA context switching
  arm64/sme: Implement streaming SVE context switching
  ...

* for-next/stacktrace:
  : Stacktrace cleanups.
  arm64: stacktrace: align with common naming
  arm64: stacktrace: rename stackframe to unwind_state
  arm64: stacktrace: rename unwinder functions
  arm64: stacktrace: make struct stackframe private to stacktrace.c
  arm64: stacktrace: delete PCS comment
  arm64: stacktrace: remove NULL task check from unwind_frame()

* for-next/fault-in-subpage:
  : btrfs search_ioctl() live-lock fix using fault_in_subpage_writeable().
  btrfs: Avoid live-lock in search_ioctl() on hardware with sub-page faults
  arm64: Add support for user sub-page fault probing
  mm: Add fault_in_subpage_writeable() to probe at sub-page granularity

* for-next/misc:
  : Miscellaneous patches.
  arm64: Kconfig.platforms: Add comments
  arm64: Kconfig: Fix indentation and add comments
  arm64: mm: avoid writable executable mappings in kexec/hibernate code
  arm64: lds: move special code sections out of kernel exec segment
  arm64/hugetlb: Implement arm64 specific huge_ptep_get()
  arm64/hugetlb: Use ptep_get() to get the pte value of a huge page
  arm64: mm: Make arch_faults_on_old_pte() check for migratability
  arm64: mte: Clean up user tag accessors
  arm64/hugetlb: Drop TLB flush from get_clear_flush()
  arm64: Declare non global symbols as static
  arm64: mm: Cleanup useless parameters in zone_sizes_init()
  arm64: fix types in copy_highpage()
  arm64: Set ARCH_NR_GPIO to 2048 for ARCH_APPLE
  arm64: cputype: Avoid overflow using MIDR_IMPLEMENTOR_MASK
  arm64: document the boot requirements for MTE
  arm64/mm: Compute PTRS_PER_[PMD|PUD] independently of PTRS_PER_PTE

* for-next/ftrace:
  : ftrace cleanups.
  arm64/ftrace: Make function graph use ftrace directly
  ftrace: cleanup ftrace_graph_caller enable and disable

* for-next/crashkernel:
  : Support for crashkernel reservations above ZONE_DMA.
  arm64: kdump: Do not allocate crash low memory if not needed
  docs: kdump: Update the crashkernel description for arm64
  of: Support more than one crash kernel regions for kexec -s
  of: fdt: Add memory for devices by DT property "linux,usable-memory-range"
  arm64: kdump: Reimplement crashkernel=X
  arm64: Use insert_resource() to simplify code
  kdump: return -ENOENT if required cmdline option does not exist

Convert FAR_ELx to automatic register generation as per DDI0487H.a. In the
architecture these registers have a single field "named" as "Faulting
Virtual Address for synchronous exceptions taken to ELx" occupying the
entire register, in order to fit in with the requirement to describe the
contents of the register I have created a single field named ADDR.

No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-7-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert DACR32_EL2 to automatic register generation as per DDI0487H.a, no
functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-6-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert CSSELR_EL1 to automatic generation as per DDI0487H.a, no functional
change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-5-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert the CPACR system register definitions to be automatically generated
using the definitions in DDI0487H.a. The kernel does have some additional
definitions for subfields of SMEN, FPEN and ZEN which are not identified as
distinct subfields in the architecture so the definitions are not updated
as part of this patch.

No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-4-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert the various CONTEXTIDR_ELx register definitions to be automatically
generated following the definitions in DDI0487H.a. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-3-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert CLIDR_EL1 to be automatically generated with definition as per
DDI0487H.a. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220520161639.324236-2-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

If CONFIG_ARM64_SVE is not set:

    arch/arm64/kernel/fpsimd.c:294:13: warning: ‘sve_free’ defined but not used [-Wunused-function]

Fix this by moving sve_free() and __sve_free() into the existing section
protected by "#ifdef CONFIG_ARM64_SVE", now the last user outside that
section has been removed.

Fixes: a1259dd8 ("arm64/sve: Delay freeing memory in fpsimd_flush_thread()")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/cd633284683c24cb9469f8ff429915aedf67f868.1652798894.git.geert+renesas@glider.beSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add trailing comments to endmenu statements for better readability.
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Link: https://lore.kernel.org/r/20220517141648.331976-3-juergh@canonical.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The convention for indentation seems to be a single tab. Help text is
further indented by an additional two whitespaces. Fix the lines that
violate these rules.

While add it, add trailing comments to endif and endmenu statements for
better readability.
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Link: https://lore.kernel.org/r/20220517141648.331976-2-juergh@canonical.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The temporary mappings of the low-level kexec and hibernate helpers are
created with both writable and executable attributes, which is not
necessary here, and generally best avoided. So use read-only, executable
attributes instead.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220429131347.3621090-3-ardb@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

There are a few code sections that are emitted into the kernel's
executable .text segment simply because they contain code, but are
actually never executed via this mapping, so they can happily live in a
region that gets mapped without executable permissions, reducing the
risk of being gadgetized.

Note that the kexec and hibernate region contents are always copied into
a fresh page, and so there is no need to align them as long as the
overall size of each is below 4 KiB.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220429131347.3621090-2-ardb@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Now we use huge_ptep_get() to get the pte value of a hugetlb page,
however it will only return one specific pte value for the CONT-PTE
or CONT-PMD size hugetlb on ARM64 system, which can contain several
continuous pte or pmd entries with same page table attributes. And it
will not take into account the subpages' dirty or young bits of a
CONT-PTE/PMD size hugetlb page.

So the huge_ptep_get() is inconsistent with huge_ptep_get_and_clear(),
which already takes account the dirty or young bits for any subpages
in this CONT-PTE/PMD size hugetlb [1]. Meanwhile we can miss dirty or
young flags statistics for hugetlb pages with current huge_ptep_get(),
such as the gather_hugetlb_stats() function, and CONT-PTE/PMD hugetlb
monitoring with DAMON.

Thus define an ARM64 specific huge_ptep_get() implementation as well as
enabling __HAVE_ARCH_HUGE_PTEP_GET, that will take into account any
subpages' dirty or young bits for CONT-PTE/PMD size hugetlb page, for
those functions that want to check the dirty and young flags of a hugetlb
page.

[1] https://lore.kernel.org/linux-mm/85bd80b4-b4fd-0d3f-a2e5-149559f2f387@oracle.com/Suggested-by: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/624109a80ac4bbdf1e462dfa0b49e9f7c31a7c0d.1652496622.git.baolin.wang@linux.alibaba.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The original huge_ptep_get() on ARM64 is just a wrapper of ptep_get(),
which will not take into account any contig-PTEs dirty and access bits.
Meanwhile we will implement a new ARM64-specific huge_ptep_get()
interface in following patch, which will take into account any contig-PTEs
dirty and access bits. To keep the same efficient logic to get the pte
value, change to use ptep_get() as a preparation.
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/5113ed6e103f995e1d0f0c9fda0373b761bbcad2.1652496622.git.baolin.wang@linux.alibaba.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

When "crashkernel=X,high" is specified, the specified "crashkernel=Y,low"
memory is not required in the following corner cases:
1. If both CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, it means
   that the devices can access any memory.
2. If the system memory is small, the crash high memory may be allocated
   from the DMA zones. If that happens, there's no need to allocate
   another crash low memory because there's already one.

Add condition '(crash_base >= CRASH_ADDR_LOW_MAX)' to determine whether
the 'high' memory is allocated above DMA zones. Note: when both
CONFIG_ZONE_DMA and CONFIG_ZONE_DMA32 are disabled, the entire physical
memory is DMA accessible, CRASH_ADDR_LOW_MAX equals 'PHYS_MASK + 1'.
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Acked-by: Baoquan He <bhe@redhat.com>
Link: https://lore.kernel.org/r/20220511032033.426-1-thunder.leizhen@huawei.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert the various ZCR instances to automatic generation, no functional
changes expected.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-13-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert SVCR to automatic generation, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-12-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert SMPRI_EL1 to be generated. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-11-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

No functional change should be seen from converting SMPRIMAP_EL2 to be
generated.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-10-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Automatically generate the defines for SMIDR_EL1, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-9-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Convert SMCR to use the register definition code, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-8-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add a statement for RAZ bitfields to the automatic register generation
script. Nothing is emitted to the header for these fields.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220510161208.631259-7-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The defines for SVCR call it SVCR_EL0 however the architecture calls the
register SVCR with no _EL0 suffix. In preparation for generating the sysreg
definitions rename to match the architecture, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-6-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The bitfield definitions for SVCR have a SYS_ added to the names of the
constant which will be a problem for automatic generation. Remove the
prefixes, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-5-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

We currently have a non-standard SYS_ prefix in the constants generated
for SMIDR_EL1 bitfields. Drop this in preparation for automatic register
definition generation, no functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-4-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The SVE and SVE length configuration field LEN have constants specifying
their width called _SIZE rather than the more normal _WIDTH, in preparation
for automatic generation rename to _WIDTH. No functional change.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-3-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently (as of DDI0487H.a) the architecture defines the vector length
control field in ZCR and SMCR as being 4 bits wide with an additional 5
bits reserved above it marked as RAZ/WI for future expansion. The kernel
currently attempts to anticipate such expansion by treating these extra
bits as part of the LEN field but this will be inconvenient when we start
generating the defines and would cause problems in the event that the
architecture goes a different direction with these fields. Let's instead
change the defines to reflect the currently defined architecture, we can
update in future as needed.

No change in behaviour should be seen in any system, even emulated systems
using the maximum allowed vector length for the current architecture.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220510161208.631259-2-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

* for-next/sme: (29 commits)
  : Scalable Matrix Extensions support.
  arm64/sve: Make kernel FPU protection RT friendly
  arm64/sve: Delay freeing memory in fpsimd_flush_thread()
  arm64/sme: More sensibly define the size for the ZA register set
  arm64/sme: Fix NULL check after kzalloc
  arm64/sme: Add ID_AA64SMFR0_EL1 to __read_sysreg_by_encoding()
  arm64/sme: Provide Kconfig for SME
  KVM: arm64: Handle SME host state when running guests
  KVM: arm64: Trap SME usage in guest
  KVM: arm64: Hide SME system registers from guests
  arm64/sme: Save and restore streaming mode over EFI runtime calls
  arm64/sme: Disable streaming mode and ZA when flushing CPU state
  arm64/sme: Add ptrace support for ZA
  arm64/sme: Implement ptrace support for streaming mode SVE registers
  arm64/sme: Implement ZA signal handling
  arm64/sme: Implement streaming SVE signal handling
  arm64/sme: Disable ZA and streaming mode when handling signals
  arm64/sme: Implement traps and syscall handling for SME
  arm64/sme: Implement ZA context switching
  arm64/sme: Implement streaming SVE context switching
  arm64/sme: Implement SVCR context switching
  ...

In case a distribution enables branch protection by default do as we do for
the main kernel and explicitly disable branch protection when building the
test case for having BTI disabled to ensure it doesn't get turned on by the
toolchain defaults.
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220516182213.727589-1-broonie@kernel.orgSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Non RT kernels need to protect FPU against preemption and bottom half
processing. This is achieved by disabling bottom halves via
local_bh_disable() which implictly disables preemption.

On RT kernels this protection mechanism is not sufficient because
local_bh_disable() does not disable preemption. It serializes bottom half
related processing via a CPU local lock.

As bottom halves are running always in thread context on RT kernels
disabling preemption is the proper choice as it implicitly prevents bottom
half processing.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Acked-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220505163207.85751-3-bigeasy@linutronix.deSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

fpsimd_flush_thread() invokes kfree() via sve_free()+sme_free() within a
preempt disabled section which is not working on -RT.

Delay freeing of memory until preemption is enabled again.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220505163207.85751-2-bigeasy@linutronix.deSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch_faults_on_old_pte() relies on the calling context being
non-preemptible. CONFIG_PREEMPT_RT turns the PTE lock into a sleepable
spinlock, which doesn't disable preemption once acquired, triggering the
warning in arch_faults_on_old_pte().

It does however disable migration, ensuring the task remains on the same
CPU during the entirety of the critical section, making the read of
cpu_has_hw_af() safe and stable.

Make arch_faults_on_old_pte() check cant_migrate() instead of preemptible().

Cc: Valentin Schneider <vschneid@redhat.com>
Suggested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Link: https://lore.kernel.org/r/20220127192437.1192957-1-valentin.schneider@arm.comAcked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220505163207.85751-4-bigeasy@linutronix.deSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

Invoking user_ldst to explicitly add a post-increment of 0 is silly.
Just use a normal USER() annotation and save the redundant instruction.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Tong Tiangen <tongtiangen@huawei.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220420030418.3189040-6-tongtiangen@huawei.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>

The "bti" selftests are built with -nostdlib, which apparently
automatically creates a statically linked binary, which is what we want
and need for BTI (to avoid interactions with the dynamic linker).

However this is not true when building a PIE binary, which some
toolchains (Ubuntu) configure as the default.
When compiling btitest with such a toolchain, it will create a
dynamically linked binary, which will probably fail some tests, as the
dynamic linker might not support BTI:
===================
TAP version 13
1..18
not ok 1 nohint_func/call_using_br_x0
not ok 2 nohint_func/call_using_br_x16
not ok 3 nohint_func/call_using_blr
....
===================

To make sure we create static binaries, add an explicit -static on the
linker command line. This forces static linking even if the toolchain
defaults to PIE builds, and fixes btitest runs on BTI enabled machines.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Mark Brown <broonie@kernel.org>
Fixes: 314bcbf0 ("kselftest: arm64: Add BTI tests")
Link: https://lore.kernel.org/r/20220511172129.2078337-1-andre.przywara@arm.comSigned-off-by: Catalin Marinas <catalin.marinas@arm.com>