<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/arch/arm64/include/asm/processor.h, branch v5.6</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>Merge branches 'for-next/elf-hwcap-docs', 'for-next/smccc-conduit-cleanup', 'for-next/zone-dma', 'for-next/relax-icc_pmr_el1-sync', 'for-next/double-page-fault', 'for-next/misc', 'for-next/kselftest-arm64-signal' and 'for-next/kaslr-diagnostics' into for-next/core</title>
<updated>2019-11-08T17:46:11+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2019-11-08T17:46:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=6be22809e5c8f286877127e8a24c13c959b9fb4e'/>
<id>6be22809e5c8f286877127e8a24c13c959b9fb4e</id>
<content type='text'>
* for-next/elf-hwcap-docs:
  : Update the arm64 ELF HWCAP documentation
  docs/arm64: cpu-feature-registers: Rewrite bitfields that don't follow [e, s]
  docs/arm64: cpu-feature-registers: Documents missing visible fields
  docs/arm64: elf_hwcaps: Document HWCAP_SB
  docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value

* for-next/smccc-conduit-cleanup:
  : SMC calling convention conduit clean-up
  firmware: arm_sdei: use common SMCCC_CONDUIT_*
  firmware/psci: use common SMCCC_CONDUIT_*
  arm: spectre-v2: use arm_smccc_1_1_get_conduit()
  arm64: errata: use arm_smccc_1_1_get_conduit()
  arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

* for-next/zone-dma:
  : Reintroduction of ZONE_DMA for Raspberry Pi 4 support
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
  dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
  arm64: Make arm64_dma32_phys_limit static
  arm64: mm: Fix unused variable warning in zone_sizes_init
  mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type'
  arm64: use both ZONE_DMA and ZONE_DMA32
  arm64: rename variables used to calculate ZONE_DMA32's size
  arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys()

* for-next/relax-icc_pmr_el1-sync:
  : Relax ICC_PMR_EL1 (GICv3) accesses when ICC_CTLR_EL1.PMHE is clear
  arm64: Document ICC_CTLR_EL3.PMHE setting requirements
  arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear

* for-next/double-page-fault:
  : Avoid a double page fault in __copy_from_user_inatomic() if hw does not support auto Access Flag
  mm: fix double page fault on arm64 if PTE_AF is cleared
  x86/mm: implement arch_faults_on_old_pte() stub on x86
  arm64: mm: implement arch_faults_on_old_pte() on arm64
  arm64: cpufeature: introduce helper cpu_has_hw_af()

* for-next/misc:
  : Various fixes and clean-ups
  arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
  arm64: mm: Remove MAX_USER_VA_BITS definition
  arm64: mm: simplify the page end calculation in __create_pgd_mapping()
  arm64: print additional fault message when executing non-exec memory
  arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
  arm64: pgtable: Correct typo in comment
  arm64: docs: cpu-feature-registers: Document ID_AA64PFR1_EL1
  arm64: cpufeature: Fix typos in comment
  arm64/mm: Poison initmem while freeing with free_reserved_area()
  arm64: use generic free_initrd_mem()
  arm64: simplify syscall wrapper ifdeffery

* for-next/kselftest-arm64-signal:
  : arm64-specific kselftest support with signal-related test-cases
  kselftest: arm64: fake_sigreturn_misaligned_sp
  kselftest: arm64: fake_sigreturn_bad_size
  kselftest: arm64: fake_sigreturn_duplicated_fpsimd
  kselftest: arm64: fake_sigreturn_missing_fpsimd
  kselftest: arm64: fake_sigreturn_bad_size_for_magic0
  kselftest: arm64: fake_sigreturn_bad_magic
  kselftest: arm64: add helper get_current_context
  kselftest: arm64: extend test_init functionalities
  kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht]
  kselftest: arm64: mangle_pstate_invalid_daif_bits
  kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils
  kselftest: arm64: extend toplevel skeleton Makefile

* for-next/kaslr-diagnostics:
  : Provide diagnostics on boot for KASLR
  arm64: kaslr: Check command line before looking for a seed
  arm64: kaslr: Announce KASLR status on boot
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* for-next/elf-hwcap-docs:
  : Update the arm64 ELF HWCAP documentation
  docs/arm64: cpu-feature-registers: Rewrite bitfields that don't follow [e, s]
  docs/arm64: cpu-feature-registers: Documents missing visible fields
  docs/arm64: elf_hwcaps: Document HWCAP_SB
  docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value

* for-next/smccc-conduit-cleanup:
  : SMC calling convention conduit clean-up
  firmware: arm_sdei: use common SMCCC_CONDUIT_*
  firmware/psci: use common SMCCC_CONDUIT_*
  arm: spectre-v2: use arm_smccc_1_1_get_conduit()
  arm64: errata: use arm_smccc_1_1_get_conduit()
  arm/arm64: smccc/psci: add arm_smccc_1_1_get_conduit()

* for-next/zone-dma:
  : Reintroduction of ZONE_DMA for Raspberry Pi 4 support
  arm64: mm: reserve CMA and crashkernel in ZONE_DMA32
  dma/direct: turn ARCH_ZONE_DMA_BITS into a variable
  arm64: Make arm64_dma32_phys_limit static
  arm64: mm: Fix unused variable warning in zone_sizes_init
  mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum zone_type'
  arm64: use both ZONE_DMA and ZONE_DMA32
  arm64: rename variables used to calculate ZONE_DMA32's size
  arm64: mm: use arm64_dma_phys_limit instead of calling max_zone_dma_phys()

* for-next/relax-icc_pmr_el1-sync:
  : Relax ICC_PMR_EL1 (GICv3) accesses when ICC_CTLR_EL1.PMHE is clear
  arm64: Document ICC_CTLR_EL3.PMHE setting requirements
  arm64: Relax ICC_PMR_EL1 accesses when ICC_CTLR_EL1.PMHE is clear

* for-next/double-page-fault:
  : Avoid a double page fault in __copy_from_user_inatomic() if hw does not support auto Access Flag
  mm: fix double page fault on arm64 if PTE_AF is cleared
  x86/mm: implement arch_faults_on_old_pte() stub on x86
  arm64: mm: implement arch_faults_on_old_pte() on arm64
  arm64: cpufeature: introduce helper cpu_has_hw_af()

* for-next/misc:
  : Various fixes and clean-ups
  arm64: kpti: Add NVIDIA's Carmel core to the KPTI whitelist
  arm64: mm: Remove MAX_USER_VA_BITS definition
  arm64: mm: simplify the page end calculation in __create_pgd_mapping()
  arm64: print additional fault message when executing non-exec memory
  arm64: psci: Reduce the waiting time for cpu_psci_cpu_kill()
  arm64: pgtable: Correct typo in comment
  arm64: docs: cpu-feature-registers: Document ID_AA64PFR1_EL1
  arm64: cpufeature: Fix typos in comment
  arm64/mm: Poison initmem while freeing with free_reserved_area()
  arm64: use generic free_initrd_mem()
  arm64: simplify syscall wrapper ifdeffery

* for-next/kselftest-arm64-signal:
  : arm64-specific kselftest support with signal-related test-cases
  kselftest: arm64: fake_sigreturn_misaligned_sp
  kselftest: arm64: fake_sigreturn_bad_size
  kselftest: arm64: fake_sigreturn_duplicated_fpsimd
  kselftest: arm64: fake_sigreturn_missing_fpsimd
  kselftest: arm64: fake_sigreturn_bad_size_for_magic0
  kselftest: arm64: fake_sigreturn_bad_magic
  kselftest: arm64: add helper get_current_context
  kselftest: arm64: extend test_init functionalities
  kselftest: arm64: mangle_pstate_invalid_mode_el[123][ht]
  kselftest: arm64: mangle_pstate_invalid_daif_bits
  kselftest: arm64: mangle_pstate_invalid_compat_toggle and common utils
  kselftest: arm64: extend toplevel skeleton Makefile

* for-next/kaslr-diagnostics:
  : Provide diagnostics on boot for KASLR
  arm64: kaslr: Check command line before looking for a seed
  arm64: kaslr: Announce KASLR status on boot
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Remove MAX_USER_VA_BITS definition</title>
<updated>2019-11-06T11:19:25+00:00</updated>
<author>
<name>Bhupesh Sharma</name>
<email>bhsharma@redhat.com</email>
</author>
<published>2019-11-04T21:56:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=218564b164ad9d283d3cb3d5367705726123a610'/>
<id>218564b164ad9d283d3cb3d5367705726123a610</id>
<content type='text'>
commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition")
introduced the MAX_USER_VA_BITS definition, which was used to support
the arm64 mm use-cases where the user-space could use 52-bit virtual
addresses whereas the kernel-space would still could a maximum of 48-bit
virtual addressing.

But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel
VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence
there is no longer any scenario where user VA != kernel VA size
(even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true).

Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to
VA_BITS (maximum VA space size) in all possible use-cases. Note that
even though the 'vabits_actual' value would be 48 for arm64 hardware
which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52
is enabled), VA_BITS would still be set to a value 52. Hence this change
would be safe in all possible VA address space combinations.

Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Steve Capper &lt;steve.capper@arm.com&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: kexec@lists.infradead.org
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Bhupesh Sharma &lt;bhsharma@redhat.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 9b31cf493ffa ("arm64: mm: Introduce MAX_USER_VA_BITS definition")
introduced the MAX_USER_VA_BITS definition, which was used to support
the arm64 mm use-cases where the user-space could use 52-bit virtual
addresses whereas the kernel-space would still could a maximum of 48-bit
virtual addressing.

But, now with commit b6d00d47e81a ("arm64: mm: Introduce 52-bit Kernel
VAs"), we removed the 52-bit user/48-bit kernel kconfig option and hence
there is no longer any scenario where user VA != kernel VA size
(even with CONFIG_ARM64_FORCE_52BIT enabled, the same is true).

Hence we can do away with the MAX_USER_VA_BITS macro as it is equal to
VA_BITS (maximum VA space size) in all possible use-cases. Note that
even though the 'vabits_actual' value would be 48 for arm64 hardware
which don't support LVA-8.2 extension (even when CONFIG_ARM64_VA_BITS_52
is enabled), VA_BITS would still be set to a value 52. Hence this change
would be safe in all possible VA address space combinations.

Cc: James Morse &lt;james.morse@arm.com&gt;
Cc: Will Deacon &lt;will@kernel.org&gt;
Cc: Steve Capper &lt;steve.capper@arm.com&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: linux-kernel@vger.kernel.org
Cc: kexec@lists.infradead.org
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Signed-off-by: Bhupesh Sharma &lt;bhsharma@redhat.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: entry-common: don't touch daif before bp-hardening</title>
<updated>2019-10-28T11:22:54+00:00</updated>
<author>
<name>James Morse</name>
<email>james.morse@arm.com</email>
</author>
<published>2019-10-25T16:42:16+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=bfe298745afc9548ad9344a9a3f26c81fd1a76c4'/>
<id>bfe298745afc9548ad9344a9a3f26c81fd1a76c4</id>
<content type='text'>
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Julien Thierry &lt;julien.thierry.kdev@gmail.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The previous patches mechanically transformed the assembly version of
entry.S to entry-common.c for synchronous exceptions.

The C version of local_daif_restore() doesn't quite do the same thing
as the assembly versions if pseudo-NMI is in use. In particular,
| local_daif_restore(DAIF_PROCCTX_NOIRQ)
will still allow pNMI to be delivered. This is not the behaviour
do_el0_ia_bp_hardening() and do_sp_pc_abort() want as it should not
be possible for the PMU handler to run as an NMI until the bp-hardening
sequence has run.

The bp-hardening calls were placed where they are because this was the
first C code to run after the relevant exceptions. As we've now moved
that point earlier, move the checks and calls earlier too.

This makes it clearer that this stuff runs before any kind of exception,
and saves modifying PSTATE twice.

Signed-off-by: James Morse &lt;james.morse@arm.com&gt;
Reviewed-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Julien Thierry &lt;julien.thierry.kdev@gmail.com&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64, mm: move generic mmap layout functions to mm</title>
<updated>2019-09-24T22:54:11+00:00</updated>
<author>
<name>Alexandre Ghiti</name>
<email>alex@ghiti.fr</email>
</author>
<published>2019-09-23T22:38:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=67f3977f805b34cf0e41090679800d2091d41d49'/>
<id>67f3977f805b34cf0e41090679800d2091d41d49</id>
<content type='text'>
arm64 handles top-down mmap layout in a way that can be easily reused by
other architectures, so make it available in mm.  It then introduces a new
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other
architectures to benefit from those functions.  Note that this new config
depends on MMU being enabled, if selected without MMU support, a warning
will be thrown.

Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Suggested-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
arm64 handles top-down mmap layout in a way that can be easily reused by
other architectures, so make it available in mm.  It then introduces a new
config ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT that can be set by other
architectures to benefit from those functions.  Note that this new config
depends on MMU being enabled, if selected without MMU support, a warning
will be thrown.

Link: http://lkml.kernel.org/r/20190730055113.23635-5-alex@ghiti.fr
Signed-off-by: Alexandre Ghiti &lt;alex@ghiti.fr&gt;
Suggested-by: Christoph Hellwig &lt;hch@infradead.org&gt;
Acked-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Acked-by: Kees Cook &lt;keescook@chromium.org&gt;
Reviewed-by: Christoph Hellwig &lt;hch@lst.de&gt;
Reviewed-by: Luis Chamberlain &lt;mcgrof@kernel.org&gt;
Cc: Albert Ou &lt;aou@eecs.berkeley.edu&gt;
Cc: Alexander Viro &lt;viro@zeniv.linux.org.uk&gt;
Cc: James Hogan &lt;jhogan@kernel.org&gt;
Cc: Palmer Dabbelt &lt;palmer@sifive.com&gt;
Cc: Paul Burton &lt;paul.burton@mips.com&gt;
Cc: Ralf Baechle &lt;ralf@linux-mips.org&gt;
Cc: Russell King &lt;linux@armlinux.org.uk&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge branches 'for-next/52-bit-kva', 'for-next/cpu-topology', 'for-next/error-injection', 'for-next/perf', 'for-next/psci-cpuidle', 'for-next/rng', 'for-next/smpboot', 'for-next/tbi' and 'for-next/tlbi' into for-next/core</title>
<updated>2019-08-30T11:46:12+00:00</updated>
<author>
<name>Will Deacon</name>
<email>will@kernel.org</email>
</author>
<published>2019-08-30T11:46:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ac12cf85d682a2c1948210c65f7fb21ef01dd9f6'/>
<id>ac12cf85d682a2c1948210c65f7fb21ef01dd9f6</id>
<content type='text'>
* for-next/52-bit-kva: (25 commits)
  Support for 52-bit virtual addressing in kernel space

* for-next/cpu-topology: (9 commits)
  Move CPU topology parsing into core code and add support for ACPI 6.3

* for-next/error-injection: (2 commits)
  Support for function error injection via kprobes

* for-next/perf: (8 commits)
  Support for i.MX8 DDR PMU and proper SMMUv3 group validation

* for-next/psci-cpuidle: (7 commits)
  Move PSCI idle code into a new CPUidle driver

* for-next/rng: (4 commits)
  Support for 'rng-seed' property being passed in the devicetree

* for-next/smpboot: (3 commits)
  Reduce fragility of secondary CPU bringup in debug configurations

* for-next/tbi: (10 commits)
  Introduce new syscall ABI with relaxed requirements for pointer tags

* for-next/tlbi: (6 commits)
  Handle spurious page faults arising from kernel space
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
* for-next/52-bit-kva: (25 commits)
  Support for 52-bit virtual addressing in kernel space

* for-next/cpu-topology: (9 commits)
  Move CPU topology parsing into core code and add support for ACPI 6.3

* for-next/error-injection: (2 commits)
  Support for function error injection via kprobes

* for-next/perf: (8 commits)
  Support for i.MX8 DDR PMU and proper SMMUv3 group validation

* for-next/psci-cpuidle: (7 commits)
  Move PSCI idle code into a new CPUidle driver

* for-next/rng: (4 commits)
  Support for 'rng-seed' property being passed in the devicetree

* for-next/smpboot: (3 commits)
  Reduce fragility of secondary CPU bringup in debug configurations

* for-next/tbi: (10 commits)
  Introduce new syscall ABI with relaxed requirements for pointer tags

* for-next/tlbi: (6 commits)
  Handle spurious page faults arising from kernel space
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Remove vabits_user</title>
<updated>2019-08-09T10:17:27+00:00</updated>
<author>
<name>Steve Capper</name>
<email>steve.capper@arm.com</email>
</author>
<published>2019-08-07T15:55:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=2c624fe68715e76eba1a7089f91e122310dc663c'/>
<id>2c624fe68715e76eba1a7089f91e122310dc663c</id>
<content type='text'>
Previous patches have enabled 52-bit kernel + user VAs and there is no
longer any scenario where user VA != kernel VA size.

This patch removes the, now redundant, vabits_user variable and replaces
usage with vabits_actual where appropriate.

Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Previous patches have enabled 52-bit kernel + user VAs and there is no
longer any scenario where user VA != kernel VA size.

This patch removes the, now redundant, vabits_user variable and replaces
usage with vabits_actual where appropriate.

Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: mm: Introduce VA_BITS_MIN</title>
<updated>2019-08-09T10:17:16+00:00</updated>
<author>
<name>Steve Capper</name>
<email>steve.capper@arm.com</email>
</author>
<published>2019-08-07T15:55:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=90ec95cda91a021d82351c976896a63aa364ebf1'/>
<id>90ec95cda91a021d82351c976896a63aa364ebf1</id>
<content type='text'>
In order to support 52-bit kernel addresses detectable at boot time, the
kernel needs to know the most conservative VA_BITS possible should it
need to fall back to this quantity due to lack of hardware support.

A new compile time constant VA_BITS_MIN is introduced in this patch and
it is employed in the KASAN end address, KASLR, and EFI stub.

For Arm, if 52-bit VA support is unavailable the fallback is to 48-bits.

In other words: VA_BITS_MIN = min (48, VA_BITS)

Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
In order to support 52-bit kernel addresses detectable at boot time, the
kernel needs to know the most conservative VA_BITS possible should it
need to fall back to this quantity due to lack of hardware support.

A new compile time constant VA_BITS_MIN is introduced in this patch and
it is employed in the KASAN end address, KASLR, and EFI stub.

For Arm, if 52-bit VA support is unavailable the fallback is to 48-bits.

In other words: VA_BITS_MIN = min (48, VA_BITS)

Reviewed-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Steve Capper &lt;steve.capper@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Introduce prctl() options to control the tagged user addresses ABI</title>
<updated>2019-08-06T17:08:45+00:00</updated>
<author>
<name>Catalin Marinas</name>
<email>catalin.marinas@arm.com</email>
</author>
<published>2019-07-23T17:58:39+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=63f0c60379650d82250f22e4cf4137ef3dc4f43d'/>
<id>63f0c60379650d82250f22e4cf4137ef3dc4f43d</id>
<content type='text'>
It is not desirable to relax the ABI to allow tagged user addresses into
the kernel indiscriminately. This patch introduces a prctl() interface
for enabling or disabling the tagged ABI with a global sysctl control
for preventing applications from enabling the relaxed ABI (meant for
testing user-space prctl() return error checking without reconfiguring
the kernel). The ABI properties are inherited by threads of the same
application and fork()'ed children but cleared on execve(). A Kconfig
option allows the overall disabling of the relaxed ABI.

The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle
MTE-specific settings like imprecise vs precise exceptions.

Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
It is not desirable to relax the ABI to allow tagged user addresses into
the kernel indiscriminately. This patch introduces a prctl() interface
for enabling or disabling the tagged ABI with a global sysctl control
for preventing applications from enabling the relaxed ABI (meant for
testing user-space prctl() return error checking without reconfiguring
the kernel). The ABI properties are inherited by threads of the same
application and fork()'ed children but cleared on execve(). A Kconfig
option allows the overall disabling of the relaxed ABI.

The PR_SET_TAGGED_ADDR_CTRL will be expanded in the future to handle
MTE-specific settings like imprecise vs precise exceptions.

Reviewed-by: Kees Cook &lt;keescook@chromium.org&gt;
Signed-off-by: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Signed-off-by: Andrey Konovalov &lt;andreyknvl@google.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: remove pointless __KERNEL__ guards</title>
<updated>2019-08-05T10:06:33+00:00</updated>
<author>
<name>Mark Rutland</name>
<email>mark.rutland@arm.com</email>
</author>
<published>2019-07-08T16:36:40+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b907b80d7ae7b2b65ef9f534f3e9a32ce6a4b539'/>
<id>b907b80d7ae7b2b65ef9f534f3e9a32ce6a4b539</id>
<content type='text'>
For a number of years, UAPI headers have been split from kernel-internal
headers. The latter are never exposed to userspace, and always built
with __KERNEL__ defined.

Most headers under arch/arm64 don't have __KERNEL__ guards, but there
are a few stragglers lying around. To make things more consistent, and
to set a good example going forward, let's remove these redundant
__KERNEL__ guards.

In a couple of cases, a trailing #endif lacked a comment describing its
corresponding #if or #ifdef, so these are fixes up at the same time.

Guards in auto-generated crypto code are left as-is, as these guards are
generated by scripting imported from the upstream openssl project
scripts. Guards in UAPI headers are left as-is, as these can be included
by userspace or the kernel.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For a number of years, UAPI headers have been split from kernel-internal
headers. The latter are never exposed to userspace, and always built
with __KERNEL__ defined.

Most headers under arch/arm64 don't have __KERNEL__ guards, but there
are a few stragglers lying around. To make things more consistent, and
to set a good example going forward, let's remove these redundant
__KERNEL__ guards.

In a couple of cases, a trailing #endif lacked a comment describing its
corresponding #if or #ifdef, so these are fixes up at the same time.

Guards in auto-generated crypto code are left as-is, as these guards are
generated by scripting imported from the upstream openssl project
scripts. Guards in UAPI headers are left as-is, as these can be included
by userspace or the kernel.

There should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland &lt;mark.rutland@arm.com&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Catalin Marinas &lt;catalin.marinas@arm.com&gt;
Cc: Will Deacon &lt;will.deacon@arm.com&gt;
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>arm64: Force SSBS on context switch</title>
<updated>2019-07-22T14:24:16+00:00</updated>
<author>
<name>Marc Zyngier</name>
<email>marc.zyngier@arm.com</email>
</author>
<published>2019-07-22T13:53:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=cbdf8a189a66001c36007bf0f5c975d0376c5c3a'/>
<id>cbdf8a189a66001c36007bf0f5c975d0376c5c3a</id>
<content type='text'>
On a CPU that doesn't support SSBS, PSTATE[12] is RES0.  In a system
where only some of the CPUs implement SSBS, we end-up losing track of
the SSBS bit across task migration.

To address this issue, let's force the SSBS bit on context switch.

Fixes: 8f04e8e6e29c ("arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3")
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
[will: inverted logic and added comments]
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
On a CPU that doesn't support SSBS, PSTATE[12] is RES0.  In a system
where only some of the CPUs implement SSBS, we end-up losing track of
the SSBS bit across task migration.

To address this issue, let's force the SSBS bit on context switch.

Fixes: 8f04e8e6e29c ("arm64: ssbd: Add support for PSTATE.SSBS rather than trapping to EL3")
Signed-off-by: Marc Zyngier &lt;marc.zyngier@arm.com&gt;
[will: inverted logic and added comments]
Signed-off-by: Will Deacon &lt;will@kernel.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
