linux-stable.git/arch/arm64/include/asm, branch v5.8

Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

2020-08-02T17:41:00+00:00

Pull KVM fixes from Paolo Bonzini:
 "Bugfixes and strengthening the validity checks on inputs from new
  userspace APIs.

  Now I know why I shouldn't prepare pull requests on the weekend, it's
  hard to concentrate if your son is shouting about his latest Minecraft
  builds in your ear. Fortunately all the patches were ready and I just
  had to check the test results..."

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  KVM: SVM: Fix disable pause loop exit/pause filtering capability on SVM
  KVM: LAPIC: Prevent setting the tscdeadline timer if the lapic is hw disabled
  KVM: arm64: Don't inherit exec permission across page-table levels
  KVM: arm64: Prevent vcpu_has_ptrauth from generating OOL functions
  KVM: nVMX: check for invalid hdr.vmx.flags
  KVM: nVMX: check for required but missing VMCS12 in KVM_SET_NESTED_STATE
  selftests: kvm: do not set guest mode flag

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

2020-07-31T16:36:03+00:00

Pull arm64 fixes from Will Deacon:
 "The main one is to fix the build after Willy's per-cpu entropy changes
  this week. Although that was already resolved elsewhere, the arm64 fix
  here is useful cleanup anyway.

  Other than that, we've got a fix for building with Clang's integrated
  assembler and a fix to make our IPv4 checksumming robust against
  invalid header lengths (this only seems to be triggerable by injected
  errors).

   - Fix build breakage due to circular headers

   - Fix build regression when using Clang's integrated assembler

   - Fix IPv4 header checksum code to deal with invalid length field

   - Fix broken path for Arm PMU entry in MAINTAINERS"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  MAINTAINERS: Include drivers subdirs for ARM PMU PROFILING AND DEBUGGING entry
  arm64: csum: Fix handling of bad packets
  arm64: Drop unnecessary include from asm/smp.h
  arm64/alternatives: move length validation inside the subsection

arm64: csum: Fix handling of bad packets

2020-07-30T16:01:38+00:00

Although iph is expected to point to at least 20 bytes of valid memory,
ihl may be bogus, for example on reception of a corrupt packet. If it
happens to be less than 5, we really don't want to run away and
dereference 16GB worth of memory until it wraps back to exactly zero...

Fixes: 0e455d8e80aa ("arm64: Implement optimised IP checksum helpers")
Reported-by: guodeqing 
Signed-off-by: Robin Murphy 
Signed-off-by: Will Deacon

arm64: Drop unnecessary include from asm/smp.h

2020-07-30T15:55:32+00:00

asm/pointer_auth.h is not needed anymore in asm/smp.h, as 62a679cb2825
("arm64: simplify ptrauth initialization") removed the keys from the
secondary_data structure.

This also cures a compilation issue introduced by f227e3ec3b5c
("random32: update the net random state on interrupt and activity").

Fixes: 62a679cb2825 ("arm64: simplify ptrauth initialization")
Fixes: f227e3ec3b5c ("random32: update the net random state on interrupt and activity")
Acked-by: Catalin Marinas 
Signed-off-by: Marc Zyngier 
Signed-off-by: Will Deacon

arm64/alternatives: move length validation inside the subsection

2020-07-30T15:50:14+00:00

Commit f7b93d42945c ("arm64/alternatives: use subsections for replacement
sequences") breaks LLVM's integrated assembler, because due to its
one-pass design, it cannot compute instruction sequence lengths before the
layout for the subsection has been finalized. This change fixes the build
by moving the .org directives inside the subsection, so they are processed
after the subsection layout is known.

Fixes: f7b93d42945c ("arm64/alternatives: use subsections for replacement sequences")
Signed-off-by: Sami Tolvanen 
Link: https://github.com/ClangBuiltLinux/linux/issues/1078
Link: https://lore.kernel.org/r/20200730153701.3892953-1-samitolvanen@google.com
Signed-off-by: Will Deacon

KVM: arm64: Prevent vcpu_has_ptrauth from generating OOL functions

2020-07-28T08:03:57+00:00

So far, vcpu_has_ptrauth() is implemented in terms of system_supports_*_auth()
calls, which are declared "inline". In some specific conditions (clang
and SCS), the "inline" very much turns into an "out of line", which
leads to a fireworks when this predicate is evaluated on a non-VHE
system (right at the beginning of __hyp_handle_ptrauth).

Instead, make sure vcpu_has_ptrauth gets expanded inline by directly
using the cpus_have_final_cap() helpers, which are __always_inline,
generate much better code, and are the only thing that make sense when
running at EL2 on a nVHE system.

Fixes: 29eb5a3c57f7 ("KVM: arm64: Handle PtrAuth traps early")
Reported-by: Nathan Chancellor 
Reported-by: Nick Desaulniers 
Signed-off-by: Marc Zyngier 
Tested-by: Nathan Chancellor 
Reviewed-by: Nathan Chancellor 
Link: https://lore.kernel.org/r/20200722162231.3689767-1-maz@kernel.org

Merge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux into master

2020-07-17T22:27:52+00:00

Pull arm64 fixes from Will Deacon:
 "A batch of arm64 fixes.

  Although the diffstat is a bit larger than we'd usually have at this
  stage, a decent amount of it is the addition of comments describing
  our syscall tracing behaviour, and also a sweep across all the modular
  arm64 PMU drivers to make them rebust against unloading and unbinding.

  There are a couple of minor things kicking around at the moment (CPU
  errata and module PLTs for very large modules), but I'm not expecting
  any significant changes now for us in 5.8.

   - Fix kernel text addresses for relocatable images booting using EFI
     and with KASLR disabled so that they match the vmlinux ELF binary.

   - Fix unloading and unbinding of PMU driver modules.

   - Fix generic mmiowb() when writeX() is called from preemptible
     context (reported by the riscv folks).

   - Fix ptrace hardware single-step interactions with signal handlers,
     system calls and reverse debugging.

   - Fix reporting of 64-bit x0 register for 32-bit tasks via
     'perf_regs'.

   - Add comments describing syscall entry/exit tracing ABI"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  drivers/perf: Prevent forced unbinding of PMU drivers
  asm-generic/mmiowb: Allow mmiowb_set_pending() when preemptible()
  arm64: Use test_tsk_thread_flag() for checking TIF_SINGLESTEP
  arm64: ptrace: Use NO_SYSCALL instead of -1 in syscall_trace_enter()
  arm64: syscall: Expand the comment about ptrace and syscall(-1)
  arm64: ptrace: Add a comment describing our syscall entry/exit trap ABI
  arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return
  arm64: ptrace: Override SPSR.SS when single-stepping is enabled
  arm64: ptrace: Consistently use pseudo-singlestep exceptions
  drivers/perf: Fix kernel panic when rmmod PMU modules during perf sampling
  efi/libstub/arm64: Retain 2MB kernel Image alignment if !KASLR

arm64: compat: Ensure upper 32 bits of x0 are zero on syscall return

2020-07-16T10:41:31+00:00

Although we zero the upper bits of x0 on entry to the kernel from an
AArch32 task, we do not clear them on the exception return path and can
therefore expose 64-bit sign extended syscall return values to userspace
via interfaces such as the 'perf_regs' ABI, which deal exclusively with
64-bit registers.

Explicitly clear the upper 32 bits of x0 on return from a compat system
call.

Cc: 
Cc: Mark Rutland 
Cc: Keno Fischer 
Cc: Luis Machado 
Signed-off-by: Will Deacon

arm64: ptrace: Override SPSR.SS when single-stepping is enabled

2020-07-16T10:41:21+00:00

Luis reports that, when reverse debugging with GDB, single-step does not
function as expected on arm64:

  | I've noticed, under very specific conditions, that a PTRACE_SINGLESTEP
  | request by GDB won't execute the underlying instruction. As a consequence,
  | the PC doesn't move, but we return a SIGTRAP just like we would for a
  | regular successful PTRACE_SINGLESTEP request.

The underlying problem is that when the CPU register state is restored
as part of a reverse step, the SPSR.SS bit is cleared and so the hardware
single-step state can transition to the "active-pending" state, causing
an unexpected step exception to be taken immediately if a step operation
is attempted.

In hindsight, we probably shouldn't have exposed SPSR.SS in the pstate
accessible by the GPR regset, but it's a bit late for that now. Instead,
simply prevent userspace from configuring the bit to a value which is
inconsistent with the TIF_SINGLESTEP state for the task being traced.

Cc: 
Cc: Mark Rutland 
Cc: Keno Fischer 
Link: https://lore.kernel.org/r/1eed6d69-d53d-9657-1fc9-c089be07f98c@linaro.org
Reported-by: Luis Machado 
Tested-by: Luis Machado 
Signed-off-by: Will Deacon

arm64: ptrace: Consistently use pseudo-singlestep exceptions

2020-07-16T10:41:07+00:00

Although the arm64 single-step state machine can be fast-forwarded in
cases where we wish to generate a SIGTRAP without actually executing an
instruction, this has two major limitations outside of simply skipping
an instruction due to emulation.

1. Stepping out of a ptrace signal stop into a signal handler where
   SIGTRAP is blocked. Fast-forwarding the stepping state machine in
   this case will result in a forced SIGTRAP, with the handler reset to
   SIG_DFL.

2. The hardware implicitly fast-forwards the state machine when executing
   an SVC instruction for issuing a system call. This can interact badly
   with subsequent ptrace stops signalled during the execution of the
   system call (e.g. SYSCALL_EXIT or seccomp traps), as they may corrupt
   the stepping state by updating the PSTATE for the tracee.

Resolve both of these issues by injecting a pseudo-singlestep exception
on entry to a signal handler and also on return to userspace following a
system call.

Cc: 
Cc: Mark Rutland 
Tested-by: Luis Machado 
Reported-by: Keno Fischer 
Signed-off-by: Will Deacon