linux.git/arch/arm64/kernel/Makefile, branch v5.12

Merge branch 'for-next/vdso' into for-next/core

2021-02-12T15:17:42+00:00

vDSO build improvements.

* for-next/vdso:
  arm64: Support running gen_vdso_offsets.sh with BSD userland.
  arm64: do not descend to vdso directories twice

arm64: cpufeature: Add an early command-line cpufeature override facility

2021-02-09T13:50:52+00:00

In order to be able to override CPU features at boot time,
let's add a command line parser that matches options of the
form "cpureg.feature=value", and store the corresponding
value into the override val/mask pair.

No features are currently defined, so no expected change in
functionality.

Signed-off-by: Marc Zyngier 
Acked-by: David Brazdil 
Reviewed-by: Catalin Marinas 
Link: https://lore.kernel.org/r/20210208095732.3267263-14-maz@kernel.org
Signed-off-by: Will Deacon

arm64: do not descend to vdso directories twice

2021-01-20T12:18:46+00:00

arm64 descends into each vdso directory twice; first in vdso_prepare,
second during the ordinary build process.

PPC mimicked it and uncovered a problem [1]. In the first descend,
Kbuild directly visits the vdso directories, therefore it does not
inherit subdir-ccflags-y from upper directories.

This means the command line parameters may differ between the two.
If it happens, the offset values in the generated headers might be
different from real offsets of vdso.so in the kernel.

This potential danger should be avoided. The vdso directories are
built in the vdso_prepare stage, so the second descend is unneeded.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNARAkJ3_-4gX0VA2UkapbOftuzfSTVMBbgbw=HD8n7N+7w@mail.gmail.com/T/#ma10dcb961fda13f36d42d58fa6cb2da988b7e73a

Signed-off-by: Masahiro Yamada 
Link: https://lore.kernel.org/r/20201218024540.1102650-1-masahiroy@kernel.org
Signed-off-by: Will Deacon

arm64: scs: use vmapped IRQ and SDEI shadow stacks

2020-12-01T11:23:34+00:00

Use scs_alloc() to allocate also IRQ and SDEI shadow stacks instead of
using statically allocated stacks.

Signed-off-by: Sami Tolvanen 
Acked-by: Will Deacon 
Link: https://lore.kernel.org/r/20201130233442.2562064-3-samitolvanen@google.com
[will: Move CONFIG_SHADOW_CALL_STACK check into init_irq_scs()]
Signed-off-by: Will Deacon

Merge branch 'for-next/mte' into for-next/core

2020-10-02T11:16:11+00:00

Add userspace support for the Memory Tagging Extension introduced by
Armv8.5.

(Catalin Marinas and others)
* for-next/mte: (30 commits)
  arm64: mte: Fix typo in memory tagging ABI documentation
  arm64: mte: Add Memory Tagging Extension documentation
  arm64: mte: Kconfig entry
  arm64: mte: Save tags when hibernating
  arm64: mte: Enable swap of tagged pages
  mm: Add arch hooks for saving/restoring tags
  fs: Handle intra-page faults in copy_mount_options()
  arm64: mte: ptrace: Add NT_ARM_TAGGED_ADDR_CTRL regset
  arm64: mte: ptrace: Add PTRACE_{PEEK,POKE}MTETAGS support
  arm64: mte: Allow {set,get}_tagged_addr_ctrl() on non-current tasks
  arm64: mte: Restore the GCR_EL1 register after a suspend
  arm64: mte: Allow user control of the generated random tags via prctl()
  arm64: mte: Allow user control of the tag check mode via prctl()
  mm: Allow arm64 mmap(PROT_MTE) on RAM-based files
  arm64: mte: Validate the PROT_MTE request via arch_validate_flags()
  mm: Introduce arch_validate_flags()
  arm64: mte: Add PROT_MTE support to mmap() and mprotect()
  mm: Introduce arch_calc_vm_flag_bits()
  arm64: mte: Tags-aware aware memcmp_pages() implementation
  arm64: Avoid unnecessary clear_user_page() indirection
  ...

Merge branch 'for-next/ghostbusters' into for-next/core

2020-10-02T11:15:24+00:00

Fix and subsequently rewrite Spectre mitigations, including the addition
of support for PR_SPEC_DISABLE_NOEXEC.

(Will Deacon and Marc Zyngier)
* for-next/ghostbusters: (22 commits)
  arm64: Add support for PR_SPEC_DISABLE_NOEXEC prctl() option
  arm64: Pull in task_stack_page() to Spectre-v4 mitigation code
  KVM: arm64: Allow patching EL2 vectors even with KASLR is not enabled
  arm64: Get rid of arm64_ssbd_state
  KVM: arm64: Convert ARCH_WORKAROUND_2 to arm64_get_spectre_v4_state()
  KVM: arm64: Get rid of kvm_arm_have_ssbd()
  KVM: arm64: Simplify handling of ARCH_WORKAROUND_2
  arm64: Rewrite Spectre-v4 mitigation code
  arm64: Move SSBD prctl() handler alongside other spectre mitigation code
  arm64: Rename ARM64_SSBD to ARM64_SPECTRE_V4
  arm64: Treat SSBS as a non-strict system feature
  arm64: Group start_thread() functions together
  KVM: arm64: Set CSV2 for guests on hardware unaffected by Spectre-v2
  arm64: Rewrite Spectre-v2 mitigation code
  arm64: Introduce separate file for spectre mitigations and reporting
  arm64: Rename ARM64_HARDEN_BRANCH_PREDICTOR to ARM64_SPECTRE_V2
  KVM: arm64: Simplify install_bp_hardening_cb()
  KVM: arm64: Replace CONFIG_KVM_INDIRECT_VECTORS with CONFIG_RANDOMIZE_BASE
  arm64: Remove Spectre-related CONFIG_* options
  arm64: Run ARCH_WORKAROUND_2 enabling code on all CPUs
  ...

arm64: Move SSBD prctl() handler alongside other spectre mitigation code

2020-09-29T15:08:16+00:00

As part of the spectre consolidation effort to shift all of the ghosts
into their own proton pack, move all of the horrible SSBD prctl() code
out of its own 'ssbd.c' file.

Signed-off-by: Will Deacon

arm64: Introduce separate file for spectre mitigations and reporting

2020-09-29T15:08:15+00:00

The spectre mitigation code is spread over a few different files, which
makes it both hard to follow, but also hard to remove it should we want
to do that in future.

Introduce a new file for housing the spectre mitigations, and populate
it with the spectre-v1 reporting code to start with.

Signed-off-by: Will Deacon

arm64: Remove Spectre-related CONFIG_* options

2020-09-29T15:08:15+00:00

The spectre mitigations are too configurable for their own good, leading
to confusing logic trying to figure out when we should mitigate and when
we shouldn't. Although the plethora of command-line options need to stick
around for backwards compatibility, the default-on CONFIG options that
depend on EXPERT can be dropped, as the mitigations only do anything if
the system is vulnerable, a mitigation is available and the command-line
hasn't disabled it.

Remove CONFIG_HARDEN_BRANCH_PREDICTOR and CONFIG_ARM64_SSBD in favour of
enabling this code unconditionally.

Signed-off-by: Will Deacon

arm64: get rid of TEXT_OFFSET

2020-09-07T14:00:52+00:00

TEXT_OFFSET serves no purpose, and for this reason, it was redefined
as 0x0 in the v5.8 timeframe. Since this does not appear to have caused
any issues that require us to revisit that decision, let's get rid of the
macro entirely, along with any references to it.

Signed-off-by: Ard Biesheuvel 
Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org
Signed-off-by: Will Deacon