In order to allow the disintegration of the per-vcpu sysreg array,
let's introduce a new helper (ctxt_sys_reg()) that returns the
in-memory copy of a system register, picked from a given context.

__vcpu_sys_reg() is rewritten to use this helper.
Signed-off-by: NMarc Zyngier <maz@kernel.org>

Since we often have a precise idea of the level we're dealing with
when invalidating TLBs, we can provide it to as a hint to our
invalidation helper.
Reviewed-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>

As we are about to reuse our stage 2 page table manipulation code for
shadow stage 2 page tables in the context of nested virtualization, we
are going to manage multiple stage 2 page tables for a single VM.

This requires some pretty invasive changes to our data structures,
which moves the vmid and pgd pointers into a separate structure and
change pretty much all of our mmu code to operate on this structure
instead.

The new structure is called struct kvm_s2_mmu.

There is no intended functional change by this patch alone.
Reviewed-by: NJames Morse <james.morse@arm.com>
Reviewed-by: NAlexandru Elisei <alexandru.elisei@arm.com>
[Designed data structure layout in collaboration]
Signed-off-by: NChristoffer Dall <christoffer.dall@arm.com>
Co-developed-by: NMarc Zyngier <maz@kernel.org>
[maz: Moved the last_vcpu_ran down to the S2 MMU structure as well]
Signed-off-by: NMarc Zyngier <maz@kernel.org>

Add a level-hinted TLB invalidation helper that only gets used if
ARMv8.4-TTL gets detected.
Reviewed-by: NAlexandru Elisei <alexandru.elisei@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>

Advertise bits [58:55] as reserved for SW in the S2 descriptors.
Reviewed-by: NAndrew Scull <ascull@google.com>
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>

In order to reduce the cost of TLB invalidation, the ARMv8.4 TTL
feature allows TLBs to be issued with a level allowing for quicker
invalidation.

Let's detect the feature for now. Further patches will implement
its actual usage.

Reviewed-by : Suzuki K Polose <suzuki.poulose@arm.com>
Reviewed-by: NCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>

With VHE and nVHE executable code completely separated, remove build config
that disabled GCOV/KASAN/UBSAN/KCOV instrumentation for VHE as these now
execute under the same memory mappings as the rest of the kernel.

No violations are currently being reported by either KASAN or UBSAN.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-16-dbrazdil@google.com

With nVHE code now fully separated from the rest of the kernel, the effects of
the __hyp_text macro (which had to be applied on all nVHE code) can be
achieved with build rules instead. The macro used to:
  (a) move code to .hyp.text ELF section, now done by renaming .text using
      `objcopy`, and
  (b) `notrace` and `__noscs` would negate effects of CC_FLAGS_FTRACE and
      CC_FLAGS_SCS, respectivelly, now those flags are  erased from
      KBUILD_CFLAGS (same way as in EFI stub).

Note that by removing __hyp_text from code shared with VHE, all VHE code is now
compiled into .text and without `notrace` and `__noscs`.

Use of '.pushsection .hyp.text' removed from assembly files as this is now also
covered by the build rules.

For MAINTAINERS: if needed to re-run, uses of macro were removed with the
following command. Formatting was fixed up manually.

  find arch/arm64/kvm/hyp -type f -name '*.c' -o -name '*.h' \
       -exec sed -i 's/ __hyp_text//g' {} +
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-15-dbrazdil@google.com

The following files in hyp/ contain only code shared by VHE/nVHE:
  vgic-v3-sr.c, aarch32.c, vgic-v2-cpuif-proxy.c, entry.S, fpsimd.S
Compile them under both configurations. Deletions in image-vars.h reflect
eliminated dependencies of nVHE code on the rest of the kernel.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-14-dbrazdil@google.com

timer-sr.c contains a HVC handler for setting CNTVOFF_EL2 and two helper
functions for controlling access to physical counter. The former is used by
both VHE/nVHE and is duplicated, the latter are used only by nVHE and moved
to nvhe/timer-sr.c.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-13-dbrazdil@google.com

sysreg-sr.c contains KVM's code for saving/restoring system registers, with
some code shared between VHE/nVHE. These common routines are moved to
a header file, VHE-specific code is moved to vhe/sysreg-sr.c and nVHE-specific
code to nvhe/sysreg-sr.c.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-12-dbrazdil@google.com

debug-sr.c contains KVM's code for context-switching debug registers, with some
code shared between VHE/nVHE. These common routines are moved to a header file,
VHE-specific code is moved to vhe/debug-sr.c and nVHE-specific code to
nvhe/debug-sr.c.

Functions are slightly refactored to move code hidden behind `has_vhe()` checks
to the corresponding .c files.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-11-dbrazdil@google.com

switch.c implements context-switching for KVM, with large parts shared between
VHE/nVHE. These common routines are moved to a header file, VHE-specific code
is moved to vhe/switch.c and nVHE-specific code is moved to nvhe/switch.c.

Previously __kvm_vcpu_run needed a different symbol name for VHE/nVHE. This
is cleaned up and the caller in arm.c simplified.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-10-dbrazdil@google.com

tlb.c contains code for flushing the TLB, with code shared between VHE/nVHE.
Because common code is small, duplicate tlb.c and specialize each copy for
VHE/nVHE.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-9-dbrazdil@google.com

hyp-init.S contains the identity mapped initialisation code for the
non-VHE code that runs at EL2. It is only used for non-VHE.

Adjust code that calls into this to use the prefixed symbol name.
Signed-off-by: NAndrew Scull <ascull@google.com>
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-8-dbrazdil@google.com

hyp-entry.S contains implementation of KVM hyp vectors. This code is mostly
shared between VHE/nVHE, therefore compile it under both VHE and nVHE build
rules. nVHE-specific host HVC handler is hidden behind __KVM_NVHE_HYPERVISOR__.

Adjust code which selects which KVM hyp vecs to install to choose the correct
VHE/nVHE symbol.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-7-dbrazdil@google.com

Once hyp functions are moved to a hyp object, they will have prefixed symbols.
This change declares and gets the address of the prefixed version for calls to
the hyp functions.

To aid migration, the hyp functions that have not yet moved have their prefixed
versions aliased to their non-prefixed version. This begins with all the hyp
functions being listed and will reduce to none of them once the migration is
complete.
Signed-off-by: NAndrew Scull <ascull@google.com>

[David: Extracted kvm_call_hyp nVHE branches into own helper macros, added
        comments around symbol aliases.]
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-6-dbrazdil@google.com

Build system compiles hyp code with macros specifying if the code belongs
to VHE or nVHE. Use these macros to evaluate has_vhe() at compile time.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-5-dbrazdil@google.com

Add new folders arch/arm64/kvm/hyp/{vhe,nvhe} and Makefiles for building code
that runs in EL2 under VHE/nVHE KVM, repsectivelly. Add an include folder for
hyp-specific header files which will include code common to VHE/nVHE.

Build nVHE code with -D__KVM_NVHE_HYPERVISOR__, VHE code with
-D__KVM_VHE_HYPERVISOR__.

Under nVHE compile each source file into a `.hyp.tmp.o` object first, then
prefix all its symbols with "__kvm_nvhe_" using `objcopy` and produce
a `.hyp.o`. Suffixes were chosen so that it would be possible for VHE and nVHE
to share some source files, but compiled with different CFLAGS.

The nVHE ELF symbol prefix is added to kallsyms.c as ignored. EL2-only symbols
will never appear in EL1 stack traces.

Due to symbol prefixing, add a section in image-vars.h for aliases of symbols
that are defined in nVHE EL2 and accessed by kernel in EL1 or vice versa.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-4-dbrazdil@google.com

This snippet of assembly is used by cpu_errata.c to overwrite parts of KVM hyp
vector. Move it to its own source file and change its ELF section to .rodata.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-3-dbrazdil@google.com

__hyp_call_panic_nvhe contains inline assembly which did not declare
its dependency on the __hyp_panic_string symbol.

The static-declared string has previously been kept alive because of a use in
__hyp_call_panic_vhe. Fix this in preparation for separating the source files
between VHE and nVHE when the two users land in two different compilation
units. The static variable otherwise gets dropped when compiling the nVHE
source file, causing an undefined symbol linker error later.
Signed-off-by: NDavid Brazdil <dbrazdil@google.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200625131420.71444-2-dbrazdil@google.com

This reverts commit 7b8e0188.

Initially, STiH410-B2260 was supposed to be secured, that's why
l2c_write_sec was stubbed to avoid secure register access from
non secure world.

But by default, STiH410-B2260 is running in non secure mode,
so L2 cache register accesses are authorized, l2c_write_sec stub
is not needed.

With this patch, L2 cache is configured and performance are enhanced.

Link: https://lore.kernel.org/r/20200618172456.29475-1-patrice.chotard@st.comSigned-off-by: NPatrice Chotard <patrice.chotard@st.com>
Cc: Alain Volmat <alain.volmat@st.com>
Signed-off-by: NArnd Bergmann <arnd@arndb.de>

Use PAGE_KERNEL_ROX directly instead of allocating RWX and setting the
page read-only just after the allocation.

Link: http://lkml.kernel.org/r/20200618064307.32739-3-hch@lst.deSigned-off-by: NChristoph Hellwig <hch@lst.de>
Acked-by: NDavid Hildenbrand <david@redhat.com>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: Vitaly Kuznetsov <vkuznets@redhat.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "fix a hyperv W^X violation and remove vmalloc_exec"

Dexuan reported a W^X violation due to the fact that the hyper hypercall
page due switching it to be allocated using vmalloc_exec.

The problem is that PAGE_KERNEL_EXEC as used by vmalloc_exec actually
sets writable permissions in the pte.  This series fixes the issue by
switching to the low-level __vmalloc_node_range interface that allows
specifing more detailed permissions instead.  It then also open codes
the other two callers and removes the somewhat confusing vmalloc_exec
interface.

Peter noted that the hyper hypercall page allocation also has another
long standing issue in that it shouldn't use the full vmalloc but just
the module space.  This issue is so far theoretical as the allocation is
done early in the boot process.  I plan to fix it with another bigger
series for 5.9.

This patch (of 3):

Avoid a W^X violation cause by the fact that PAGE_KERNEL_EXEC includes
the writable bit.

For this resurrect the removed PAGE_KERNEL_RX definition, but as
PAGE_KERNEL_ROX to match arm64 and powerpc.

Link: http://lkml.kernel.org/r/20200618064307.32739-2-hch@lst.de
Fixes: 78bb17f7 ("x86/hyperv: use vmalloc_exec for the hypercall page")
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reported-by: NDexuan Cui <decui@microsoft.com>
Tested-by: NVitaly Kuznetsov <vkuznets@redhat.com>
Acked-by: NWei Liu <wei.liu@kernel.org>
Acked-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since v5.8-rc1 OpenRISC Linux fails to boot when DEBUG_VM is enabled.
This has been bisected to commit 42fc5414 ("mmap locking API: add
mmap_assert_locked() and mmap_assert_write_locked()").

The added locking checks exposed the issue that OpenRISC was not taking
this mmap lock when during page walks for DMA operations.  This patch
locks and unlocks the mmap lock for page walking.

Link: http://lkml.kernel.org/r/20200617090247.1680188-1-shorne@gmail.com
Fixes: 42fc5414 ("mmap locking API: add mmap_assert_locked() and mmap_assert_write_locked()"
Signed-off-by: NStafford Horne <shorne@gmail.com>
Reviewed-by: NMichel Lespinasse <walken@google.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: Steven Price <steven.price@arm.com>
Cc: Thomas Hellstrom <thellstrom@vmware.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Daniel Jordan <daniel.m.jordan@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

For linux-5.8-rc1, enable ftrace of riscv will cause boot panic:

[    2.388980] Run /sbin/init as init process
[    2.529938] init[39]: unhandled signal 4 code 0x1 at 0x0000003ff449e000
[    2.531078] CPU: 0 PID: 39 Comm: init Not tainted 5.8.0-rc1-dirty #13
[    2.532719] epc: 0000003ff449e000 ra : 0000003ff449e954 sp : 0000003fffedb900
[    2.534005]  gp : 00000000000e8528 tp : 0000003ff449d800 t0 : 000000000000001e
[    2.534965]  t1 : 000000000000000a t2 : 0000003fffedb89e s0 : 0000003fffedb920
[    2.536279]  s1 : 0000003fffedb940 a0 : 0000003ff43d4b2c a1 : 0000000000000000
[    2.537334]  a2 : 0000000000000001 a3 : 0000000000000000 a4 : fffffffffbad8000
[    2.538466]  a5 : 0000003ff449e93a a6 : 0000000000000000 a7 : 0000000000000000
[    2.539511]  s2 : 0000000000000000 s3 : 0000003ff448412c s4 : 0000000000000010
[    2.541260]  s5 : 0000000000000016 s6 : 00000000000d0a30 s7 : 0000003fffedba70
[    2.542152]  s8 : 0000000000000000 s9 : 0000000000000000 s10: 0000003fffedb960
[    2.543335]  s11: 0000000000000000 t3 : 0000000000000000 t4 : 0000003fffedb8a0
[    2.544471]  t5 : 0000000000000000 t6 : 0000000000000000
[    2.545730] status: 0000000000004020 badaddr: 00000000464c457f cause: 0000000000000002
[    2.549867] Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000004
[    2.551267] CPU: 0 PID: 1 Comm: init Not tainted 5.8.0-rc1-dirty #13
[    2.552061] Call Trace:
[    2.552626] [<ffffffe00020374a>] walk_stackframe+0x0/0xc4
[    2.553486] [<ffffffe0002039f4>] show_stack+0x40/0x4c
[    2.553995] [<ffffffe00054a6ae>] dump_stack+0x7a/0x98
[    2.554615] [<ffffffe00020b9b8>] panic+0x114/0x2f4
[    2.555395] [<ffffffe00020ebd6>] do_exit+0x89c/0x8c2
[    2.555949] [<ffffffe00020f930>] do_group_exit+0x3a/0x90
[    2.556715] [<ffffffe000219e08>] get_signal+0xe2/0x6e6
[    2.557388] [<ffffffe000202d72>] do_notify_resume+0x6a/0x37a
[    2.558089] [<ffffffe000201c16>] ret_from_exception+0x0/0xc

"ra:0x3ff449e954" is the return address of "call _mcount" in the
prologue of __vdso_gettimeofday(). Without proper relocate, pc jmp
to 0x0000003ff449e000 (vdso map base) with a illegal instruction
trap.

The solution comes from arch/arm64/kernel/vdso/Makefile:

CFLAGS_REMOVE_vgettimeofday.o = $(CC_FLAGS_FTRACE) -Os $(CC_FLAGS_SCS)

 - CC_FLAGS_SCS is ShadowCallStack feature in Clang and only
   implemented for arm64, no use for riscv.

Fixes: ad5d1122 ("riscv: use vDSO common flow to reduce the latency of the time-related functions")
Cc: stable@vger.kernel.org
Signed-off-by: NGuo Ren <guoren@linux.alibaba.com>
Reviewed-by: NVincent Chen <vincent.chen@sifive.com>
Signed-off-by: NPalmer Dabbelt <palmerdabbelt@google.com>

Add extern declarations for vDSO time-related functions to notify the
compiler these functions will be used in somewhere to avoid
"no previous prototype" compile warning.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NVincent Chen <vincent.chen@sifive.com>
Signed-off-by: NPalmer Dabbelt <palmerdabbelt@google.com>

The time related vDSO functions use a variable, vdso_data, to access the
vDSO data page to get the system time information. Because the vdso_data
for CFLAGS_vgettimeofday.o is an external variable defined in vdso.o,
the CFLAGS_vgettimeofday.o should be compiled with -fPIC to ensure
that vdso_data is addressable.
Reported-by: Nkernel test robot <lkp@intel.com>
Signed-off-by: NVincent Chen <vincent.chen@sifive.com>
Signed-off-by: NPalmer Dabbelt <palmerdabbelt@google.com>

QCOM KRYO{3,4}XX silver/LITTLE CPU cores are based on
Cortex-A55 and are SSB safe, hence add them to SSB
safelist -> arm64_ssb_cpus[].
Reported-by: NStephen Boyd <swboyd@chromium.org>
Signed-off-by: NSai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Reviewed-by: NDouglas Anderson <dianders@chromium.org>
Link: https://lore.kernel.org/r/20200625103123.7240-1-saiprakash.ranjan@codeaurora.orgSigned-off-by: NWill Deacon <will@kernel.org>

A 32-bit perf querying the registers of a compat task using REGS_ABI_32
will receive zeroes from w15, when it expects to find the PC.

Return the PC value for register dwarf register 15 when returning register
values for a compat task to perf.

Cc: <stable@vger.kernel.org>
Acked-by: NMark Rutland <mark.rutland@arm.com>
Signed-off-by: NJiping Ma <jiping.ma2@windriver.com>
Link: https://lore.kernel.org/r/1589165527-188401-1-git-send-email-jiping.ma2@windriver.com
[will: Shuffled code and added a comment]
Signed-off-by: NWill Deacon <will@kernel.org>

vmlinux.o: warning: objtool: exc_invalid_op()+0x47: call to probe_kernel_read() leaves .noinstr.text section

Since we use UD2 as a short-cut for 'CALL __WARN', treat it as such.
Have the bare exception handler do the report_bug() thing.

Fixes: 15a416e8 ("x86/entry: Treat BUG/WARN as NMI-like entries")
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: NAndy Lutomirski <luto@kernel.org>
Link: https://lkml.kernel.org/r/20200622114713.GE577403@hirez.programming.kicks-ass.net

Marco crashed in bad_iret with a Clang11/KCSAN build due to
overflowing the stack. Now that we run C code on it, expand it to a
full page.
Suggested-by: NAndy Lutomirski <luto@amacapital.net>
Reported-by: NMarco Elver <elver@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: NLai Jiangshan <jiangshanlai@gmail.com>
Tested-by: NMarco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200618144801.819246178@infradead.org

vmlinux.o: warning: objtool: fixup_bad_iret()+0x8e: call to memcpy() leaves .noinstr.text section

Worse, when KASAN there is no telling what memcpy() actually is. Force
the use of __memcpy() which is our assmebly implementation.
Reported-by: NMarco Elver <elver@google.com>
Suggested-by: NMarco Elver <elver@google.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: NMarco Elver <elver@google.com>
Link: https://lkml.kernel.org/r/20200618144801.760070502@infradead.org

QCOM KRYO{3,4}XX silver/LITTLE CPU cores are based on Cortex-A55
and are meltdown safe, hence add them to kpti_safe_list[].
Signed-off-by: NSai Prakash Ranjan <saiprakash.ranjan@codeaurora.org>
Link: https://lore.kernel.org/r/20200624123406.3472-1-saiprakash.ranjan@codeaurora.orgSigned-off-by: NWill Deacon <will@kernel.org>

Some ftrace features are broken since commit 714a8d02 ("arm64: asm:
Override SYM_FUNC_START when building the kernel with BTI"). For example
the function_graph tracer:

$ echo function_graph > /sys/kernel/debug/tracing/current_tracer
[   36.107016] WARNING: CPU: 0 PID: 115 at kernel/trace/ftrace.c:2691 ftrace_modify_all_code+0xc8/0x14c

When ftrace_modify_graph_caller() attempts to write a branch at
ftrace_graph_call, it finds the "BTI J" instruction inserted by
SYM_INNER_LABEL() instead of a NOP, and aborts.

It turns out we don't currently need the BTI landing pads inserted by
SYM_INNER_LABEL:

* ftrace_call and ftrace_graph_call are only used for runtime patching
  of the active tracer. The patched code is not reached from a branch.
* install_el2_stub is reached from a CBZ instruction, which doesn't
  change PSTATE.BTYPE.
* __guest_exit is reached from B instructions in the hyp-entry vectors,
  which aren't subject to BTI checks either.

Remove the BTI annotation from SYM_INNER_LABEL.

Fixes: 714a8d02 ("arm64: asm: Override SYM_FUNC_START when building the kernel with BTI")
Signed-off-by: NJean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: NMark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200624112253.1602786-1-jean-philippe@linaro.orgSigned-off-by: NWill Deacon <will@kernel.org>

Don't use gcc plugins for building arch/arm64/kernel/vdso/vgettimeofday.c
to avoid unneeded instrumentation.
Signed-off-by: NAlexander Popov <alex.popov@linux.com>
Link: https://lore.kernel.org/r/20200624123330.83226-4-alex.popov@linux.comSigned-off-by: NWill Deacon <will@kernel.org>

Commit 87676cfc ("arm64: vdso: Disable dwarf unwinding through the
sigreturn trampoline") unconditionally passes the '--no-eh-frame-hdr'
option to the linker when building the native vDSO in an attempt to
prevent generation of the .eh_frame_hdr section, the presence of which
has been implicated in segfaults originating from the libgcc unwinder.

Unfortunately, not all versions of binutils support this option, which
has been shown to cause build failures in linux-next:

  |   CALL    scripts/atomic/check-atomics.sh
  |   CALL    scripts/checksyscalls.sh
  |   LD      arch/arm64/kernel/vdso/vdso.so.dbg
  | ld: unrecognized option '--no-eh-frame-hdr'
  | ld: use the --help option for usage information
  | arch/arm64/kernel/vdso/Makefile:64: recipe for target
  | 'arch/arm64/kernel/vdso/vdso.so.dbg' failed
  | make[1]: *** [arch/arm64/kernel/vdso/vdso.so.dbg] Error 1
  | arch/arm64/Makefile:175: recipe for target 'vdso_prepare' failed
  | make: *** [vdso_prepare] Error 2

Only link the vDSO with '--no-eh-frame-hdr' when the linker supports it.
If we end up with the section due to linker defaults, the absence of CFI
information in the sigreturn trampoline will prevent the unwinder from
breaking.

Link: https://lore.kernel.org/r/7a7e31a8-9a7b-2428-ad83-2264f20bdc2d@hisilicon.com
Fixes: 87676cfc ("arm64: vdso: Disable dwarf unwinding through the sigreturn trampoline")
Reported-by: NShaokun Zhang <zhangshaokun@hisilicon.com>
Tested-by: NJon Hunter <jonathanh@nvidia.com>
Signed-off-by: NWill Deacon <will@kernel.org>

if of_find_device_by_node() succeed, imx6q_suspend_init() doesn't have a
corresponding put_device(). Thus add a jump target to fix the exception
handling for this function implementation.
Signed-off-by: Nyu kuai <yukuai3@huawei.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

if of_find_device_by_node() succeed, imx_suspend_alloc_ocram() doesn't
have a corresponding put_device(). Thus add a jump target to fix the
exception handling for this function implementation.

Fixes: 1579c7b9 ("ARM: imx53: Set DDR pins to high impedance when in suspend to RAM.")
Signed-off-by: Nyu kuai <yukuai3@huawei.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>

Versions of binutils prior to 2.33.1 don't understand the ELF notes that
are added by modern compilers to indicate the PAC and BTI options used
to build the code. This causes them to emit large numbers of warnings in
the form:

aarch64-linux-gnu-nm: warning: .tmp_vmlinux.kallsyms2: unsupported GNU_PROPERTY_TYPE (5) type: 0xc0000000

during the kernel build which is currently causing quite a bit of
disruption for automated build testing using clang.

In commit 15cd0e67 (arm64: Kconfig: ptrauth: Add binutils version
check to fix mismatch) we added a dependency on binutils to avoid this
issue when building with versions of GCC that emit the notes but did not
do so for clang as it was believed that the existing check for
.cfi_negate_ra_state was already requiring a new enough binutils. This
does not appear to be the case for some versions of binutils (eg, the
binutils in Debian 10) so instead refactor so we require a new enough
GNU binutils in all cases other than when we are using an old GCC
version that does not emit notes.

Other, more exotic, combinations of tools are possible such as using
clang, lld and gas together are possible and may have further problems
but rather than adding further version checks it looks like the most
robust thing will be to just test that we can build cleanly with the
configured tools but that will require more review and discussion so do
this for now to address the immediate problem disrupting build testing.
Reported-by: NKernelCI <bot@kernelci.org>
Reported-by: NNick Desaulniers <ndesaulniers@google.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Reviewed-by: NNick Desaulniers <ndesaulniers@google.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1054
Link: https://lore.kernel.org/r/20200619123550.48098-1-broonie@kernel.orgSigned-off-by: NWill Deacon <will@kernel.org>