Commit Graph

123 Commits

Author SHA1 Message Date
Linus Torvalds 032c7ed958 More arm64 updates for 5.10
- Improve performance of Spectre-v2 mitigation on Falkor CPUs (if you're lucky
   enough to have one)
 
 - Select HAVE_MOVE_PMD. This has been shown to improve mremap() performance,
   which is used heavily by the Android runtime GC, and it seems we forgot to
   enable this upstream back in 2018.
 
 - Ensure linker flags are consistent between LLVM and BFD
 
 - Fix stale comment in Spectre mitigation rework
 
 - Fix broken copyright header
 
 - Fix KASLR randomisation of the linear map
 
 - Prevent arm64-specific prctl()s from compat tasks (return -EINVAL)
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull more arm64 updates from Will Deacon:
 "A small selection of further arm64 fixes and updates. Most of these
  are fixes that came in during the merge window, with the exception of
  the HAVE_MOVE_PMD mremap() speed-up which we discussed back in 2018
  and somehow forgot to enable upstream.

   - Improve performance of Spectre-v2 mitigation on Falkor CPUs (if
     you're lucky enough to have one)

   - Select HAVE_MOVE_PMD. This has been shown to improve mremap()
     performance, which is used heavily by the Android runtime GC, and
     it seems we forgot to enable this upstream back in 2018.

   - Ensure linker flags are consistent between LLVM and BFD

   - Fix stale comment in Spectre mitigation rework

   - Fix broken copyright header

   - Fix KASLR randomisation of the linear map

   - Prevent arm64-specific prctl()s from compat tasks (return -EINVAL)"

Link: https://lore.kernel.org/kvmarm/20181108181201.88826-3-joelaf@google.com/

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: proton-pack: Update comment to reflect new function name
  arm64: spectre-v2: Favour CPU-specific mitigation at EL2
  arm64: link with -z norelro regardless of CONFIG_RELOCATABLE
  arm64: Fix a broken copyright header in gen_vdso_offsets.sh
  arm64: mremap speedup - Enable HAVE_MOVE_PMD
  arm64: mm: use single quantity to represent the PA to VA translation
  arm64: reject prctl(PR_PAC_RESET_KEYS) on compat tasks
2020-10-23 09:46:16 -07:00
Linus Torvalds 746b25b1aa Kbuild updates for v5.10
- Support 'make compile_commands.json' to generate the compilation
    database more easily, avoiding stale entries
 
  - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
    using clang-tidy
 
  - Preprocess scripts/modules.lds.S to allow CONFIG options in the module
    linker script
 
  - Drop cc-option tests from compiler flags supported by our minimal
    GCC/Clang versions
 
  - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y
 
  - Use sha1 build id for both BFD linker and LLD
 
  - Improve deb-pkg for reproducible builds and rootless builds
 
  - Remove stale, useless scripts/namespace.pl
 
  - Turn -Wreturn-type warning into error
 
  - Fix build error of deb-pkg when CONFIG_MODULES=n
 
  - Replace 'hostname' command with more portable 'uname -n'
 
  - Various Makefile cleanups
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Merge tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Support 'make compile_commands.json' to generate the compilation
   database more easily, avoiding stale entries

 - Support 'make clang-analyzer' and 'make clang-tidy' for static checks
   using clang-tidy

 - Preprocess scripts/modules.lds.S to allow CONFIG options in the
   module linker script

 - Drop cc-option tests from compiler flags supported by our minimal
   GCC/Clang versions

 - Use always 12-digits commit hash for CONFIG_LOCALVERSION_AUTO=y

 - Use sha1 build id for both BFD linker and LLD

 - Improve deb-pkg for reproducible builds and rootless builds

 - Remove stale, useless scripts/namespace.pl

 - Turn -Wreturn-type warning into error

 - Fix build error of deb-pkg when CONFIG_MODULES=n

 - Replace 'hostname' command with more portable 'uname -n'

 - Various Makefile cleanups

* tag 'kbuild-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (34 commits)
  kbuild: Use uname for LINUX_COMPILE_HOST detection
  kbuild: Only add -fno-var-tracking-assignments for old GCC versions
  kbuild: remove leftover comment for filechk utility
  treewide: remove DISABLE_LTO
  kbuild: deb-pkg: clean up package name variables
  kbuild: deb-pkg: do not build linux-headers package if CONFIG_MODULES=n
  kbuild: enforce -Werror=return-type
  scripts: remove namespace.pl
  builddeb: Add support for all required debian/rules targets
  builddeb: Enable rootless builds
  builddeb: Pass -n to gzip for reproducible packages
  kbuild: split the build log of kallsyms
  kbuild: explicitly specify the build id style
  scripts/setlocalversion: make git describe output more reliable
  kbuild: remove cc-option test of -Werror=date-time
  kbuild: remove cc-option test of -fno-stack-check
  kbuild: remove cc-option test of -fno-strict-overflow
  kbuild: move CFLAGS_{KASAN,UBSAN,KCSAN} exports to relevant Makefiles
  kbuild: remove redundant CONFIG_KASAN check from scripts/Makefile.kasan
  kbuild: do not create built-in objects for external module builds
  ...
2020-10-22 13:13:57 -07:00
Nick Desaulniers 3b92fa7485 arm64: link with -z norelro regardless of CONFIG_RELOCATABLE
With CONFIG_EXPERT=y, CONFIG_KASAN=y, CONFIG_RANDOMIZE_BASE=n,
CONFIG_RELOCATABLE=n, we observe the following failure when trying to
link the kernel image with LD=ld.lld:

error: section: .exit.data is not contiguous with other relro sections

ld.lld defaults to -z relro while ld.bfd defaults to -z norelro. This
was previously fixed, but only for CONFIG_RELOCATABLE=y.

Fixes: 3bbd3db864 ("arm64: relocatable: fix inconsistencies in linker script and options")
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20201016175339.2429280-1-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2020-10-20 12:35:37 +01:00
Linus Torvalds 34eb62d868 Orphan link sections were a long-standing source of obscure bugs,
because the heuristics that various linkers & compilers use to handle them
 (include these bits into the output image vs discarding them silently)
 are both highly idiosyncratic and also version dependent.
 
 Instead of this historically problematic mess, this tree by Kees Cook (et al)
 adds build time asserts and build time warnings if there's any orphan section
 in the kernel or if a section is not sized as expected.
 
 And because we relied on so many silent assumptions in this area, fix a metric
 ton of dependencies and some outright bugs related to this, before we can
 finally enable the checks on the x86, ARM and ARM64 platforms.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull orphan section checking from Ingo Molnar:
 "Orphan link sections were a long-standing source of obscure bugs,
  because the heuristics that various linkers & compilers use to handle
  them (include these bits into the output image vs discarding them
  silently) are both highly idiosyncratic and also version dependent.

  Instead of this historically problematic mess, this tree by Kees Cook
  (et al) adds build time asserts and build time warnings if there's any
  orphan section in the kernel or if a section is not sized as expected.

  And because we relied on so many silent assumptions in this area, fix
  a metric ton of dependencies and some outright bugs related to this,
  before we can finally enable the checks on the x86, ARM and ARM64
  platforms"

* tag 'core-build-2020-10-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  x86/boot/compressed: Warn on orphan section placement
  x86/build: Warn on orphan section placement
  arm/boot: Warn on orphan section placement
  arm/build: Warn on orphan section placement
  arm64/build: Warn on orphan section placement
  x86/boot/compressed: Add missing debugging sections to output
  x86/boot/compressed: Remove, discard, or assert for unwanted sections
  x86/boot/compressed: Reorganize zero-size section asserts
  x86/build: Add asserts for unwanted sections
  x86/build: Enforce an empty .got.plt section
  x86/asm: Avoid generating unused kprobe sections
  arm/boot: Handle all sections explicitly
  arm/build: Assert for unwanted sections
  arm/build: Add missing sections
  arm/build: Explicitly keep .ARM.attributes sections
  arm/build: Refactor linker script headers
  arm64/build: Assert for unwanted sections
  arm64/build: Add missing DWARF sections
  arm64/build: Use common DISCARDS in linker script
  arm64/build: Remove .eh_frame* sections due to unwind tables
  ...
2020-10-12 13:39:19 -07:00
Masahiro Yamada 596b0474d3 kbuild: preprocess module linker script
There was a request to preprocess the module linker script like we
do for the vmlinux one. (https://lkml.org/lkml/2020/8/21/512)

The difference between vmlinux.lds and module.lds is that the latter
is needed for external module builds, thus must be cleaned up by
'make mrproper' instead of 'make clean'. Also, it must be created
by 'make modules_prepare'.

You cannot put it in arch/$(SRCARCH)/kernel/, which is cleaned up by
'make clean'. I moved arch/$(SRCARCH)/kernel/module.lds to
arch/$(SRCARCH)/include/asm/module.lds.h, which is included from
scripts/module.lds.S.

scripts/module.lds is fine because 'make clean' keeps all the
build artifacts under scripts/.

You can add arch-specific sections in <asm/module.lds.h>.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Tested-by: Jessica Yu <jeyu@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Palmer Dabbelt <palmerdabbelt@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Jessica Yu <jeyu@kernel.org>
2020-09-25 00:36:41 +09:00
Ard Biesheuvel 120dc60d0b arm64: get rid of TEXT_OFFSET
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 <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200825135440.11288-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-09-07 15:00:52 +01:00
Kees Cook b3e5d80d0c arm64/build: Warn on orphan section placement
We don't want to depend on the linker's orphan section placement
heuristics as these can vary between linkers, and may change between
versions. All sections need to be explicitly handled in the linker
script.

With all sections now handled, enable orphan section warnings.

Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20200902025347.2504702-2-keescook@chromium.org
2020-09-03 10:28:35 +02:00
Kees Cook 6e0a66d10c arm64/build: Remove .eh_frame* sections due to unwind tables
Avoid .eh_frame* section generation by making sure both CFLAGS and AFLAGS
contain -fno-asychronous-unwind-tables and -fno-unwind-tables.

With all sources of .eh_frame now removed from the build, drop this
DISCARD so we can be alerted in the future if it returns unexpectedly
once orphan section warnings have been enabled.

Suggested-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20200821194310.3089815-11-keescook@chromium.org
2020-09-01 09:50:36 +02:00
Frank van der Linden 5d28ba5f8a arm64: vdso32: make vdso32 install conditional
vdso32 should only be installed if CONFIG_COMPAT_VDSO is enabled,
since it's not even supposed to be compiled otherwise, and arm64
builds without a 32bit crosscompiler will fail.

Fixes: 8d75785a81 ("ARM64: vdso32: Install vdso32 from vdso_install")
Signed-off-by: Frank van der Linden <fllinden@amazon.com>
Cc: stable@vger.kernel.org [5.4+]
Link: https://lore.kernel.org/r/20200827234012.19757-1-fllinden@amazon.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 13:18:48 +01:00
Sami Tolvanen 1764c3edc6 arm64: use a common .arch preamble for inline assembly
Commit 7c78f67e9b ("arm64: enable tlbi range instructions") breaks
LLVM's integrated assembler, because -Wa,-march is only passed to
external assemblers and therefore, the new instructions are not enabled
when IAS is used.

This change adds a common architecture version preamble, which can be
used in inline assembly blocks that contain instructions that require
a newer architecture version, and uses it to fix __TLBI_0 and __TLBI_1
with ARM64_TLB_RANGE.

Fixes: 7c78f67e9b ("arm64: enable tlbi range instructions")
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Link: https://github.com/ClangBuiltLinux/linux/issues/1106
Link: https://lore.kernel.org/r/20200827203608.1225689-1-samitolvanen@google.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-28 11:15:15 +01:00
Stephen Boyd 8d75785a81 ARM64: vdso32: Install vdso32 from vdso_install
Add the 32-bit vdso Makefile to the vdso_install rule so that 'make
vdso_install' installs the 32-bit compat vdso when it is compiled.

Fixes: a7f71a2c89 ("arm64: compat: Add vDSO")
Signed-off-by: Stephen Boyd <swboyd@chromium.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Acked-by: Will Deacon <will@kernel.org>
Cc: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://lore.kernel.org/r/20200818014950.42492-1-swboyd@chromium.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-08-21 19:11:44 +01:00
Linus Torvalds 145ff1ec09 arm64 and cross-arch updates for 5.9:
- Removal of the tremendously unpopular read_barrier_depends() barrier,
   which is a NOP on all architectures apart from Alpha, in favour of
   allowing architectures to override READ_ONCE() and do whatever dance
   they need to do to ensure address dependencies provide LOAD ->
   LOAD/STORE ordering. This work also offers a potential solution if
   compilers are shown to convert LOAD -> LOAD address dependencies into
   control dependencies (e.g. under LTO), as weakly ordered architectures
   will effectively be able to upgrade READ_ONCE() to smp_load_acquire().
   The latter case is not used yet, but will be discussed further at LPC.
 
 - Make the MSI/IOMMU input/output ID translation PCI agnostic, augment
   the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
   bus-specific parameter and apply the resulting changes to the device
   ID space provided by the Freescale FSL bus.
 
 - arm64 support for TLBI range operations and translation table level
   hints (part of the ARMv8.4 architecture version).
 
 - Time namespace support for arm64.
 
 - Export the virtual and physical address sizes in vmcoreinfo for
   makedumpfile and crash utilities.
 
 - CPU feature handling cleanups and checks for programmer errors
   (overlapping bit-fields).
 
 - ACPI updates for arm64: disallow AML accesses to EFI code regions and
   kernel memory.
 
 - perf updates for arm64.
 
 - Miscellaneous fixes and cleanups, most notably PLT counting
   optimisation for module loading, recordmcount fix to ignore
   relocations other than R_AARCH64_CALL26, CMA areas reserved for
   gigantic pages on 16K and 64K configurations.
 
 - Trivial typos, duplicate words.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 and cross-arch updates from Catalin Marinas:
 "Here's a slightly wider-spread set of updates for 5.9.

  Going outside the usual arch/arm64/ area is the removal of
  read_barrier_depends() series from Will and the MSI/IOMMU ID
  translation series from Lorenzo.

  The notable arm64 updates include ARMv8.4 TLBI range operations and
  translation level hint, time namespace support, and perf.

  Summary:

   - Removal of the tremendously unpopular read_barrier_depends()
     barrier, which is a NOP on all architectures apart from Alpha, in
     favour of allowing architectures to override READ_ONCE() and do
     whatever dance they need to do to ensure address dependencies
     provide LOAD -> LOAD/STORE ordering.

     This work also offers a potential solution if compilers are shown
     to convert LOAD -> LOAD address dependencies into control
     dependencies (e.g. under LTO), as weakly ordered architectures will
     effectively be able to upgrade READ_ONCE() to smp_load_acquire().
     The latter case is not used yet, but will be discussed further at
     LPC.

   - Make the MSI/IOMMU input/output ID translation PCI agnostic,
     augment the MSI/IOMMU ACPI/OF ID mapping APIs to accept an input ID
     bus-specific parameter and apply the resulting changes to the
     device ID space provided by the Freescale FSL bus.

   - arm64 support for TLBI range operations and translation table level
     hints (part of the ARMv8.4 architecture version).

   - Time namespace support for arm64.

   - Export the virtual and physical address sizes in vmcoreinfo for
     makedumpfile and crash utilities.

   - CPU feature handling cleanups and checks for programmer errors
     (overlapping bit-fields).

   - ACPI updates for arm64: disallow AML accesses to EFI code regions
     and kernel memory.

   - perf updates for arm64.

   - Miscellaneous fixes and cleanups, most notably PLT counting
     optimisation for module loading, recordmcount fix to ignore
     relocations other than R_AARCH64_CALL26, CMA areas reserved for
     gigantic pages on 16K and 64K configurations.

   - Trivial typos, duplicate words"

Link: http://lkml.kernel.org/r/20200710165203.31284-1-will@kernel.org
Link: http://lkml.kernel.org/r/20200619082013.13661-1-lorenzo.pieralisi@arm.com

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (82 commits)
  arm64: use IRQ_STACK_SIZE instead of THREAD_SIZE for irq stack
  arm64/mm: save memory access in check_and_switch_context() fast switch path
  arm64: sigcontext.h: delete duplicated word
  arm64: ptrace.h: delete duplicated word
  arm64: pgtable-hwdef.h: delete duplicated words
  bus: fsl-mc: Add ACPI support for fsl-mc
  bus/fsl-mc: Refactor the MSI domain creation in the DPRC driver
  of/irq: Make of_msi_map_rid() PCI bus agnostic
  of/irq: make of_msi_map_get_device_domain() bus agnostic
  dt-bindings: arm: fsl: Add msi-map device-tree binding for fsl-mc bus
  of/device: Add input id to of_dma_configure()
  of/iommu: Make of_map_rid() PCI agnostic
  ACPI/IORT: Add an input ID to acpi_dma_configure()
  ACPI/IORT: Remove useless PCI bus walk
  ACPI/IORT: Make iort_msi_map_rid() PCI agnostic
  ACPI/IORT: Make iort_get_device_domain IRQ domain agnostic
  ACPI/IORT: Make iort_match_node_callback walk the ACPI namespace for NC
  arm64: enable time namespace support
  arm64/vdso: Restrict splitting VVAR VMA
  arm64/vdso: Handle faults on timens page
  ...
2020-08-03 14:11:08 -07:00
Linus Torvalds 17baa44286 Various EFI fixes:
- Fix the layering violation in the use of the EFI runtime services
     availability mask in users of the 'efivars' abstraction
 
   - Revert build fix for GCC v4.8 which is no longer supported
 
   - Clean up some x86 EFI stub details, some of which are borderline bugs
     that copy around garbage into padding fields - let's fix these
     out of caution.
 
   - Fix build issues while working on RISC-V support
 
   - Avoid --whole-archive when linking the stub on arm64
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip into master

Pull EFI fixes from Ingo Molnar:
 "Various EFI fixes:

   - Fix the layering violation in the use of the EFI runtime services
     availability mask in users of the 'efivars' abstraction

   - Revert build fix for GCC v4.8 which is no longer supported

   - Clean up some x86 EFI stub details, some of which are borderline
     bugs that copy around garbage into padding fields - let's fix these
     out of caution.

   - Fix build issues while working on RISC-V support

   - Avoid --whole-archive when linking the stub on arm64"

* tag 'efi-urgent-2020-07-25' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi: Revert "efi/x86: Fix build with gcc 4"
  efi/efivars: Expose RT service availability via efivars abstraction
  efi/libstub: Move the function prototypes to header file
  efi/libstub: Fix gcc error around __umoddi3 for 32 bit builds
  efi/libstub/arm64: link stub lib.a conditionally
  efi/x86: Only copy upto the end of setup_header
  efi/x86: Remove unused variables
2020-07-25 13:18:42 -07:00
Zhenyu Ye 7c78f67e9b arm64: enable tlbi range instructions
TLBI RANGE feature instoduces new assembly instructions and only
support by binutils >= 2.30.  Add necessary Kconfig logic to allow
this to be enabled and pass '-march=armv8.4-a' to KBUILD_CFLAGS.

Signed-off-by: Zhenyu Ye <yezhenyu2@huawei.com>
Link: https://lore.kernel.org/r/20200715071945.897-3-yezhenyu2@huawei.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-07-15 16:01:01 +01:00
Masahiro Yamada c1aac64ddc efi/libstub/arm64: link stub lib.a conditionally
Since commit 799c434154 ("kbuild: thin archives make default for
all archs"), core-y is passed to the linker with --whole-archive.
Hence, the whole of stub library is linked to vmlinux.

Use libs-y so that lib.a is passed after --no-whole-archive for
conditional linking.

The unused drivers/firmware/efi/libstub/relocate.o will be dropped
for ARCH=arm64.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20200604022031.164207-1-masahiroy@kernel.org
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
2020-07-09 09:45:09 +03:00
Ard Biesheuvel 751c263bb7 arm64: remove TEXT_OFFSET randomization
TEXT_OFFSET was recently changed to 0x0, in preparation for its removal
at a later stage, and a warning is emitted into the kernel log when the
bootloader appears to have failed to take the TEXT_OFFSET image header
value into account.

Ironically, this warning itself fails to take TEXT_OFFSET into account,
and compares the kernel image's alignment modulo 2M against a hardcoded
value of 0x0, and so the warning will trigger spuriously when TEXT_OFFSET
randomization is enabled.

Given the intent to get rid of TEXT_OFFSET entirely, let's fix this
oversight by just removing support for TEXT_OFFSET randomization.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200615101939.634391-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-06-15 13:10:59 +01:00
Linus Torvalds cff11abeca Kbuild updates for v5.8
- fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32
 
  - ensure to rebuild all objects when the compiler is upgraded
 
  - exclude system headers from dependency tracking and fixdep processing
 
  - fix potential bit-size mismatch between the kernel and BPF user-mode
    helper
 
  - add the new syntax 'userprogs' to build user-space programs for the
    target architecture (the same arch as the kernel)
 
  - compile user-space sample code under samples/ for the target arch
    instead of the host arch
 
  - make headers_install fail if a CONFIG option is leaked to user-space
 
  - sanitize the output format of scripts/checkstack.pl
 
  - handle ARM 'push' instruction in scripts/checkstack.pl
 
  - error out before modpost if a module name conflict is found
 
  - error out when multiple directories are passed to M= because this
    feature is broken for a long time
 
  - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info
 
  - a lot of cleanups of modpost
 
  - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
    second pass of modpost
 
  - do not run the second pass of modpost if nothing in modules is updated
 
  - install modules.builtin(.modinfo) by 'make install' as well as by
    'make modules_install' because it is useful even when CONFIG_MODULES=n
 
  - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
    to allow users to use alternatives such as pigz, pbzip2, etc.
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Merge tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - fix warnings in 'make clean' for ARCH=um, hexagon, h8300, unicore32

 - ensure to rebuild all objects when the compiler is upgraded

 - exclude system headers from dependency tracking and fixdep processing

 - fix potential bit-size mismatch between the kernel and BPF user-mode
   helper

 - add the new syntax 'userprogs' to build user-space programs for the
   target architecture (the same arch as the kernel)

 - compile user-space sample code under samples/ for the target arch
   instead of the host arch

 - make headers_install fail if a CONFIG option is leaked to user-space

 - sanitize the output format of scripts/checkstack.pl

 - handle ARM 'push' instruction in scripts/checkstack.pl

 - error out before modpost if a module name conflict is found

 - error out when multiple directories are passed to M= because this
   feature is broken for a long time

 - add CONFIG_DEBUG_INFO_COMPRESSED to support compressed debug info

 - a lot of cleanups of modpost

 - dump vmlinux symbols out into vmlinux.symvers, and reuse it in the
   second pass of modpost

 - do not run the second pass of modpost if nothing in modules is
   updated

 - install modules.builtin(.modinfo) by 'make install' as well as by
   'make modules_install' because it is useful even when
   CONFIG_MODULES=n

 - add new command line variables, GZIP, BZIP2, LZOP, LZMA, LZ4, and XZ
   to allow users to use alternatives such as pigz, pbzip2, etc.

* tag 'kbuild-v5.8' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (96 commits)
  kbuild: add variables for compression tools
  Makefile: install modules.builtin even if CONFIG_MODULES=n
  mksysmap: Fix the mismatch of '.L' symbols in System.map
  kbuild: doc: rename LDFLAGS to KBUILD_LDFLAGS
  modpost: change elf_info->size to size_t
  modpost: remove is_vmlinux() helper
  modpost: strip .o from modname before calling new_module()
  modpost: set have_vmlinux in new_module()
  modpost: remove mod->skip struct member
  modpost: add mod->is_vmlinux struct member
  modpost: remove is_vmlinux() call in check_for_{gpl_usage,unused}()
  modpost: remove mod->is_dot_o struct member
  modpost: move -d option in scripts/Makefile.modpost
  modpost: remove -s option
  modpost: remove get_next_text() and make {grab,release_}file static
  modpost: use read_text_file() and get_line() for reading text files
  modpost: avoid false-positive file open error
  modpost: fix potential mmap'ed file overrun in get_src_version()
  modpost: add read_text_file() and get_line() helpers
  modpost: do not call get_modinfo() for vmlinux(.o)
  ...
2020-06-06 12:00:25 -07:00
Will Deacon 082af5ec50 Merge branch 'for-next/scs' into for-next/core
Support for Clang's Shadow Call Stack in the kernel
(Sami Tolvanen and Will Deacon)
* for-next/scs:
  arm64: entry-ftrace.S: Update comment to indicate that x18 is live
  scs: Move DEFINE_SCS macro into core code
  scs: Remove references to asm/scs.h from core code
  scs: Move scs_overflow_check() out of architecture code
  arm64: scs: Use 'scs_sp' register alias for x18
  scs: Move accounting into alloc/free functions
  arm64: scs: Store absolute SCS stack pointer value in thread_info
  efi/libstub: Disable Shadow Call Stack
  arm64: scs: Add shadow stacks for SDEI
  arm64: Implement Shadow Call Stack
  arm64: Disable SCS for hypervisor code
  arm64: vdso: Disable Shadow Call Stack
  arm64: efi: Restore register x18 if it was corrupted
  arm64: Preserve register x18 when CPU is suspended
  arm64: Reserve register x18 from general allocation with SCS
  scs: Disable when function graph tracing is enabled
  scs: Add support for stack usage debugging
  scs: Add page accounting for shadow call stack allocations
  scs: Add support for Clang's Shadow Call Stack (SCS)
2020-05-28 18:03:40 +01:00
Will Deacon d27865279f Merge branch 'for-next/bti' into for-next/core
Support for Branch Target Identification (BTI) in user and kernel
(Mark Brown and others)
* for-next/bti: (39 commits)
  arm64: vdso: Fix CFI directives in sigreturn trampoline
  arm64: vdso: Don't prefix sigreturn trampoline with a BTI C instruction
  arm64: bti: Fix support for userspace only BTI
  arm64: kconfig: Update and comment GCC version check for kernel BTI
  arm64: vdso: Map the vDSO text with guarded pages when built for BTI
  arm64: vdso: Force the vDSO to be linked as BTI when built for BTI
  arm64: vdso: Annotate for BTI
  arm64: asm: Provide a mechanism for generating ELF note for BTI
  arm64: bti: Provide Kconfig for kernel mode BTI
  arm64: mm: Mark executable text as guarded pages
  arm64: bpf: Annotate JITed code for BTI
  arm64: Set GP bit in kernel page tables to enable BTI for the kernel
  arm64: asm: Override SYM_FUNC_START when building the kernel with BTI
  arm64: bti: Support building kernel C code using BTI
  arm64: Document why we enable PAC support for leaf functions
  arm64: insn: Report PAC and BTI instructions as skippable
  arm64: insn: Don't assume unrecognized HINTs are skippable
  arm64: insn: Provide a better name for aarch64_insn_is_nop()
  arm64: insn: Add constants for new HINT instruction decode
  arm64: Disable old style assembly annotations
  ...
2020-05-28 18:00:51 +01:00
Sami Tolvanen da64e9d1f8 arm64: Reserve register x18 from general allocation with SCS
Reserve the x18 register from general allocation when SCS is enabled,
because the compiler uses the register to store the current task's
shadow stack pointer. Note that all external kernel modules must also be
compiled with -ffixed-x18 if the kernel has SCS enabled.

Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-15 16:35:49 +01:00
Masahiro Yamada 1ca0c2f612 kbuild: remove unused AS assignment
$(AS) is not used anywhere in the kernel build, hence commit
aa824e0c96 ("kbuild: remove AS variable") killed it.

Remove the left-over code in arch/{arm,arm64}/Makefile.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Nathan Chancellor <natechancellor@gmail.com>
Acked-by: Will Deacon <will@kernel.org>
2020-05-12 13:28:33 +09:00
Mark Brown 92e2294d87 arm64: bti: Support building kernel C code using BTI
When running with BTI enabled we need to ask the compiler to enable
generation of BTI landing pads beyond those generated as a result of
pointer authentication instructions being landing pads. Since the two
features are practically speaking unlikely to be used separately we
will make kernel mode BTI depend on pointer authentication in order
to simplify the Makefile.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20200506195138.22086-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-07 17:53:20 +01:00
Mark Brown 717b938e22 arm64: Document why we enable PAC support for leaf functions
Document the fact that we enable pointer authentication protection for
leaf functions since there is some narrow potential for ROP protection
benefits and little overhead has been observed.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20200506195138.22086-2-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-05-07 17:53:20 +01:00
Ard Biesheuvel cfa7ede20f arm64: set TEXT_OFFSET to 0x0 in preparation for removing it entirely
TEXT_OFFSET on arm64 is a historical artifact from the early days of
the arm64 port where the boot protocol was basically 'copy this image
to the base of memory + 512k', giving us 512 KB of guaranteed BSS space
to put the swapper page tables. When the arm64 Image header was added in
v3.10, it already carried the actual value of TEXT_OFFSET, to allow the
bootloader to discover it dynamically rather than hardcode it to 512 KB.

Today, this memory window is not used for any particular purpose, and
it is simply handed to the page allocator at boot. The only reason it
still exists is because of the 512k misalignment it causes with respect
to the 2 MB aligned virtual base address of the kernel, which affects
the virtual addresses of all statically allocated objects in the kernel
image.

However, with the introduction of KASLR in v4.6, we added the concept of
relocatable kernels, which rewrite all absolute symbol references at
boot anyway, and so the placement of such kernels in the physical address
space is irrelevant, provided that the minimum segment alignment is
honoured (64 KB in most cases, 128 KB for 64k pages kernels with vmap'ed
stacks enabled). This makes 0x0 and 512 KB equally suitable values for
TEXT_OFFSET on the off chance that we are dealing with boot loaders that
ignore the value passed via the header entirely.

Considering that the distros as well as Android ship KASLR-capable
kernels today, and the fact that TEXT_OFFSET was discoverable from the
Image header from the very beginning, let's change this value to 0x0, in
preparation for removing it entirely at a later date.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20200415082922.32709-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 14:38:57 +01:00
Ard Biesheuvel 4cf234943d arm64: drop GZFLAGS definition and export
Drop the definition and export of GZFLAGS, which was never referenced
on arm64, and whose last recorded use in the ARM port (on which arm64
was based original) was removed by patch

  commit 5e89d379edb5ae08b57f39dd8d91697275245cbf [*]
  Author: Russell King <rmk@flint.arm.linux.org.uk>
  Date:   Wed Oct 16 14:32:17 2002 +0100

    [ARM] Convert ARM makefiles to new kbuild (Sam Ravnborg, Kai, rmk)

[*] git commit ID based on Thomas Gleixner's historical GIT repository at
    git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20200415123049.25504-1-ardb@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2020-04-28 14:06:13 +01:00
Mark Brown b8fdef311a arm64: Always force a branch protection mode when the compiler has one
Compilers with branch protection support can be configured to enable it by
default, it is likely that distributions will do this as part of deploying
branch protection system wide. As well as the slight overhead from having
some extra NOPs for unused branch protection features this can cause more
serious problems when the kernel is providing pointer authentication to
userspace but not built for pointer authentication itself. In that case our
switching of keys for userspace can affect the kernel unexpectedly, causing
pointer authentication instructions in the kernel to corrupt addresses.

To ensure that we get consistent and reliable behaviour always explicitly
initialise the branch protection mode, ensuring that the kernel is built
the same way regardless of the compiler defaults.

Fixes: 7503197562 (arm64: add basic pointer authentication support)
Reported-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org
[catalin.marinas@arm.com: remove Kconfig option in favour of Makefile check]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-04-01 21:23:40 +01:00
Kristina Martsenko 74afda4016 arm64: compile the kernel with ptrauth return address signing
Compile all functions with two ptrauth instructions: PACIASP in the
prologue to sign the return address, and AUTIASP in the epilogue to
authenticate the return address (from the stack). If authentication
fails, the return will cause an instruction abort to be taken, followed
by an oops and killing the task.

This should help protect the kernel against attacks using
return-oriented programming. As ptrauth protects the return address, it
can also serve as a replacement for CONFIG_STACKPROTECTOR, although note
that it does not protect other parts of the stack.

The new instructions are in the HINT encoding space, so on a system
without ptrauth they execute as NOPs.

CONFIG_ARM64_PTR_AUTH now not only enables ptrauth for userspace and KVM
guests, but also automatically builds the kernel with ptrauth
instructions if the compiler supports it. If there is no compiler
support, we do not warn that the kernel was built without ptrauth
instructions.

GCC 7 and 8 support the -msign-return-address option, while GCC 9
deprecates that option and replaces it with -mbranch-protection. Support
both options.

Clang uses an external assembler hence this patch makes sure that the
correct parameters (-march=armv8.3-a) are passed down to help it recognize
the ptrauth instructions.

Ftrace function tracer works properly with Ptrauth only when
patchable-function-entry feature is present and is ensured by the
Kconfig dependency.

Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Masahiro Yamada <yamada.masahiro@socionext.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Vincenzo Frascino <Vincenzo.Frascino@arm.com> # not co-dev parts
Co-developed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Kristina Martsenko <kristina.martsenko@arm.com>
[Amit: Cover leaf function, comments, Ftrace Kconfig]
Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-18 09:50:21 +00:00
Vladimir Murzin 8bf9284d99 arm64: Turn "broken gas inst" into real config option
Use the new 'as-instr' Kconfig macro to define CONFIG_BROKEN_GAS_INST
directly, making it available everywhere.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
[will: Drop redundant 'y if' logic]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 16:35:12 +00:00
Catalin Marinas 395af86137 arm64: Move the LSE gas support detection to Kconfig
As the Kconfig syntax gained support for $(as-instr) tests, move the LSE
gas support detection from Makefile to the main arm64 Kconfig and remove
the additional CONFIG_AS_LSE definition and check.

Cc: Will Deacon <will@kernel.org>
Reviewed-by: Vladimir Murzin <vladimir.murzin@arm.com>
Tested-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 12:50:48 +00:00
Torsten Duwe 3b23e4991f arm64: implement ftrace with regs
This patch implements FTRACE_WITH_REGS for arm64, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified. This is
a building block for live-patching, where a function's arguments may be
forwarded to another function. This is also necessary to enable ftrace
and in-kernel pointer authentication at the same time, as it allows the
LR value to be captured and adjusted prior to signing.

Using GCC's -fpatchable-function-entry=N option, we can have the
compiler insert a configurable number of NOPs between the function entry
point and the usual prologue. This also ensures functions are AAPCS
compliant (e.g. disabling inter-procedural register allocation).

For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the
following:

| unsigned long bar(void);
|
| unsigned long foo(void)
| {
|         return bar() + 1;
| }

... to:

| <foo>:
|         nop
|         nop
|         stp     x29, x30, [sp, #-16]!
|         mov     x29, sp
|         bl      0 <bar>
|         add     x0, x0, #0x1
|         ldp     x29, x30, [sp], #16
|         ret

This patch builds the kernel with -fpatchable-function-entry=2,
prefixing each function with two NOPs. To trace a function, we replace
these NOPs with a sequence that saves the LR into a GPR, then calls an
ftrace entry assembly function which saves this and other relevant
registers:

| mov	x9, x30
| bl	<ftrace-entry>

Since patchable functions are AAPCS compliant (and the kernel does not
use x18 as a platform register), x9-x18 can be safely clobbered in the
patched sequence and the ftrace entry code.

There are now two ftrace entry functions, ftrace_regs_entry (which saves
all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is
allocated for each within modules.

Signed-off-by: Torsten Duwe <duwe@suse.de>
[Mark: rework asm, comments, PLTs, initialization, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Julien Thierry <jthierry@redhat.com>
Cc: Will Deacon <will@kernel.org>
2019-11-06 14:17:35 +00:00
Will Deacon 7c4791c9ef arm64: Kconfig: Make CONFIG_COMPAT_VDSO a proper Kconfig option
CONFIG_COMPAT_VDSO is defined by passing '-DCONFIG_COMPAT_VDSO' to the
compiler when the generic compat vDSO code is in use. It's much cleaner
and simpler to expose this as a proper Kconfig option (like x86 does),
so do that and remove the bodge.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:15 +01:00
Will Deacon bcaf9b57e4 arm64: vdso32: Move definition of COMPATCC into vdso32/Makefile
There's no need to export COMPATCC, so just define it locally in the
vdso32/Makefile, which is the only place where it is used.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:32:02 +01:00
Will Deacon 24ee01a927 arm64: Default to building compat vDSO with clang when CONFIG_CC_IS_CLANG
Rather than force the use of GCC for the compat cross-compiler, instead
extract the target from CROSS_COMPILE_COMPAT and pass it to clang if the
main compiler is clang.

Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 13:31:45 +01:00
Vincenzo Frascino e0de01aafc arm64: vdso32: Fix broken compat vDSO build warnings
The .config file and the generated include/config/auto.conf can
end up out of sync after a set of commands since
CONFIG_CROSS_COMPILE_COMPAT_VDSO is not updated correctly.

The sequence can be reproduced as follows:

$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- defconfig
[...]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu- menuconfig
[set CONFIG_CROSS_COMPILE_COMPAT_VDSO="arm-linux-gnueabihf-"]
$ make ARCH=arm64 CROSS_COMPILE=aarch64-linux-gnu-

Which results in:

arch/arm64/Makefile:62: CROSS_COMPILE_COMPAT not defined or empty,
the compat vDSO will not be built

even though the compat vDSO has been built:

$ file arch/arm64/kernel/vdso32/vdso.so
arch/arm64/kernel/vdso32/vdso.so: ELF 32-bit LSB pie executable, ARM,
EABI5 version 1 (SYSV), dynamically linked,
BuildID[sha1]=c67f6c786f2d2d6f86c71f708595594aa25247f6, stripped

A similar case that involves changing the configuration parameter
multiple times can be reconducted to the same family of problems.

Remove the use of CONFIG_CROSS_COMPILE_COMPAT_VDSO altogether and
instead rely on the cross-compiler prefix coming from the environment
via CROSS_COMPILE_COMPAT, much like we do for the rest of the kernel.

Cc: Will Deacon <will@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-10-07 11:07:16 +01:00
Linus Torvalds d7b0827f28 Kbuild updates for v5.4
- add modpost warn exported symbols marked as 'static' because 'static'
    and EXPORT_SYMBOL is an odd combination
 
  - break the build early if gold linker is used
 
  - optimize the Bison rule to produce .c and .h files by a single
    pattern rule
 
  - handle PREEMPT_RT in the module vermagic and UTS_VERSION
 
  - warn CONFIG options leaked to the user-space except existing ones
 
  - make single targets work properly
 
  - rebuild modules when module linker scripts are updated
 
  - split the module final link stage into scripts/Makefile.modfinal
 
  - fix the missed error code in merge_config.sh
 
  - improve the error message displayed on the attempt of the O= build
    in unclean source tree
 
  - remove 'clean-dirs' syntax
 
  - disable -Wimplicit-fallthrough warning for Clang
 
  - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC
 
  - remove ARCH_{CPP,A,C}FLAGS variables
 
  - add $(BASH) to run bash scripts
 
  - change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
    instead of the basename
 
  - stop suppressing Clang's -Wunused-function warnings when W=1
 
  - fix linux/export.h to avoid genksyms calculating CRC of trimmed
    exported symbols
 
  - misc cleanups
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Merge tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - add modpost warn exported symbols marked as 'static' because 'static'
   and EXPORT_SYMBOL is an odd combination

 - break the build early if gold linker is used

 - optimize the Bison rule to produce .c and .h files by a single
   pattern rule

 - handle PREEMPT_RT in the module vermagic and UTS_VERSION

 - warn CONFIG options leaked to the user-space except existing ones

 - make single targets work properly

 - rebuild modules when module linker scripts are updated

 - split the module final link stage into scripts/Makefile.modfinal

 - fix the missed error code in merge_config.sh

 - improve the error message displayed on the attempt of the O= build in
   unclean source tree

 - remove 'clean-dirs' syntax

 - disable -Wimplicit-fallthrough warning for Clang

 - add CONFIG_CC_OPTIMIZE_FOR_SIZE_O3 for ARC

 - remove ARCH_{CPP,A,C}FLAGS variables

 - add $(BASH) to run bash scripts

 - change *CFLAGS_<basetarget>.o to take the relative path to $(obj)
   instead of the basename

 - stop suppressing Clang's -Wunused-function warnings when W=1

 - fix linux/export.h to avoid genksyms calculating CRC of trimmed
   exported symbols

 - misc cleanups

* tag 'kbuild-v5.4' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (63 commits)
  genksyms: convert to SPDX License Identifier for lex.l and parse.y
  modpost: use __section in the output to *.mod.c
  modpost: use MODULE_INFO() for __module_depends
  export.h, genksyms: do not make genksyms calculate CRC of trimmed symbols
  export.h: remove defined(__KERNEL__), which is no longer needed
  kbuild: allow Clang to find unused static inline functions for W=1 build
  kbuild: rename KBUILD_ENABLE_EXTRA_GCC_CHECKS to KBUILD_EXTRA_WARN
  kbuild: refactor scripts/Makefile.extrawarn
  merge_config.sh: ignore unwanted grep errors
  kbuild: change *FLAGS_<basetarget>.o to take the path relative to $(obj)
  modpost: add NOFAIL to strndup
  modpost: add guid_t type definition
  kbuild: add $(BASH) to run scripts with bash-extension
  kbuild: remove ARCH_{CPP,A,C}FLAGS
  kbuild,arc: add CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE_O3 for ARC
  kbuild: Do not enable -Wimplicit-fallthrough for clang for now
  kbuild: clean up subdir-ymn calculation in Makefile.clean
  kbuild: remove unneeded '+' marker from cmd_clean
  kbuild: remove clean-dirs syntax
  kbuild: check clean srctree even earlier
  ...
2019-09-20 08:36:47 -07:00
Will Deacon 61b7cddfe8 Merge branch 'for-next/atomics' into for-next/core
* for-next/atomics: (10 commits)
  Rework LSE instruction selection to use static keys instead of alternatives
2019-08-30 12:55:39 +01:00
Will Deacon ac12cf85d6 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
* 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
2019-08-30 12:46:12 +01:00
Will Deacon 03adcbd996 arm64: atomics: Use K constraint when toolchain appears to support it
The 'K' constraint is a documented AArch64 machine constraint supported
by GCC for matching integer constants that can be used with a 32-bit
logical instruction. Unfortunately, some released compilers erroneously
accept the immediate '4294967295' for this constraint, which is later
refused by GAS at assembly time. This had led us to avoid the use of
the 'K' constraint altogether.

Instead, detect whether the compiler is up to the job when building the
kernel and pass the 'K' constraint to our 32-bit atomic macros when it
appears to be supported.

Signed-off-by: Will Deacon <will@kernel.org>
2019-08-30 11:18:40 +01:00
Masahiro Yamada 6bfa3134bd arm64: add arch/arm64/Kbuild
Use the standard obj-y form to specify the sub-directories under
arch/arm64/. No functional change intended.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-21 18:47:15 +01:00
Masahiro Yamada 10df063855 kbuild: rebuild modules when module linker scripts are updated
Currently, the timestamp of module linker scripts are not checked.
Add them to the dependency of modules so they are correctly rebuilt.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
2019-08-21 21:05:21 +09:00
Steve Capper 6bd1d0be0e arm64: kasan: Switch to using KASAN_SHADOW_OFFSET
KASAN_SHADOW_OFFSET is a constant that is supplied to gcc as a command
line argument and affects the codegen of the inline address sanetiser.

Essentially, for an example memory access:
    *ptr1 = val;
The compiler will insert logic similar to the below:
    shadowValue = *(ptr1 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET)
    if (somethingWrong(shadowValue))
        flagAnError();

This code sequence is inserted into many places, thus
KASAN_SHADOW_OFFSET is essentially baked into many places in the kernel
text.

If we want to run a single kernel binary with multiple address spaces,
then we need to do this with KASAN_SHADOW_OFFSET fixed.

Thankfully, due to the way the KASAN_SHADOW_OFFSET is used to provide
shadow addresses we know that the end of the shadow region is constant
w.r.t. VA space size:
    KASAN_SHADOW_END = ~0 >> KASAN_SHADOW_SCALE_SHIFT + KASAN_SHADOW_OFFSET

This means that if we increase the size of the VA space, the start of
the KASAN region expands into lower addresses whilst the end of the
KASAN region is fixed.

Currently the arm64 code computes KASAN_SHADOW_OFFSET at build time via
build scripts with the VA size used as a parameter. (There are build
time checks in the C code too to ensure that expected values are being
derived). It is sufficient, and indeed is a simplification, to remove
the build scripts (and build time checks) entirely and instead provide
KASAN_SHADOW_OFFSET values.

This patch removes the logic to compute the KASAN_SHADOW_OFFSET in the
arm64 Makefile, and instead we adopt the approach used by x86 to supply
offset values in kConfig. To help debug/develop future VA space changes,
the Makefile logic has been preserved in a script file in the arm64
Documentation folder.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09 11:17:11 +01:00
Steve Capper 14c127c957 arm64: mm: Flip kernel VA space
In order to allow for a KASAN shadow that changes size at boot time, one
must fix the KASAN_SHADOW_END for both 48 & 52-bit VAs and "grow" the
start address. Also, it is highly desirable to maintain the same
function addresses in the kernel .text between VA sizes. Both of these
requirements necessitate us to flip the kernel address space halves s.t.
the direct linear map occupies the lower addresses.

This patch puts the direct linear map in the lower addresses of the
kernel VA range and everything else in the higher ranges.

We need to adjust:
 *) KASAN shadow region placement logic,
 *) KASAN_SHADOW_OFFSET computation logic,
 *) virt_to_phys, phys_to_virt checks,
 *) page table dumper.

These are all small changes, that need to take place atomically, so they
are bundled into this commit.

As part of the re-arrangement, a guard region of 2MB (to preserve
alignment for fixed map) is added after the vmemmap. Otherwise the
vmemmap could intersect with IS_ERR pointers.

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Steve Capper <steve.capper@arm.com>
Signed-off-by: Will Deacon <will@kernel.org>
2019-08-09 11:16:51 +01:00
Vincenzo Frascino a22c5cf5d3 arm64: vdso: Fix Makefile regression
Using an old .config in combination with "make oldconfig" can cause
an incorrect detection of the compat compiler:

$ grep CROSS_COMPILE_COMPAT .config
CONFIG_CROSS_COMPILE_COMPAT_VDSO=""

$ make oldconfig && make
arch/arm64/Makefile:58: gcc not found, check CROSS_COMPILE_COMPAT.
Stop.

Accordingly to the section 7.2 of the GNU Make manual "Syntax of
Conditionals", "When the value results from complex expansions of
variables and functions, expansions you would consider empty may
actually contain whitespace characters and thus are not seen as
empty. However, you can use the strip function to avoid interpreting
whitespace as a non-empty value."

Fix the issue adding strip to the CROSS_COMPILE_COMPAT string
evaluation.

Reported-by: Matteo Croce <mcroce@redhat.com>
Tested-by: Matteo Croce <mcroce@redhat.com>
Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-07-31 18:08:47 +01:00
Linus Torvalds 106f1466e7 Kconfig updates for v5.3
- always require argument for --defconfig and remove the hard-coded
   arch/$(ARCH)/defconfig path
 
 - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig
 
 - some code cleanups
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Merge tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kconfig updates from Masahiro Yamada:

 - always require argument for --defconfig and remove the hard-coded
   arch/$(ARCH)/defconfig path

 - make arch/$(SRCARCH)/configs/defconfig the new default of defconfig

 - some code cleanups

* tag 'kconfig-v5.3' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild:
  kconfig: remove meaningless if-conditional in conf_read()
  kconfig: Fix spelling of sym_is_changable
  unicore32: rename unicore32_defconfig to defconfig
  kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG
  kconfig: add static qualifier to expand_string()
  kconfig: require the argument of --defconfig
  kconfig: remove always false ifeq ($(KBUILD_DEFCONFIG,) conditional
2019-07-12 16:06:27 -07:00
Vincenzo Frascino bfe801ebe8 arm64: vdso: Enable vDSO compat support
Add vDSO compat support to the arm64 build system.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Tested-by: Shijith Thotton <sthotton@marvell.com>
Tested-by: Andre Przywara <andre.przywara@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-mips@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Ralf Baechle <ralf@linux-mips.org>
Cc: Paul Burton <paul.burton@mips.com>
Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
Cc: Mark Salyzyn <salyzyn@android.com>
Cc: Peter Collingbourne <pcc@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Cc: Huw Davies <huw@codeweavers.com>
Link: https://lkml.kernel.org/r/20190621095252.32307-16-vincenzo.frascino@arm.com
2019-06-22 21:21:09 +02:00
Nathan Chancellor fa63da2ab0 arm64: Don't unconditionally add -Wno-psabi to KBUILD_CFLAGS
This is a GCC only option, which warns about ABI changes within GCC, so
unconditionally adding it breaks Clang with tons of:

warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option]

and link time failures:

ld.lld: error: undefined symbol: __efistub___stack_chk_guard
>>> referenced by arm-stub.c:73
(/home/nathan/cbl/linux/drivers/firmware/efi/libstub/arm-stub.c:73)
>>>               arm-stub.stub.o:(__efistub_install_memreserve_table)
in archive ./drivers/firmware/efi/libstub/lib.a

These failures come from the lack of -fno-stack-protector, which is
added via cc-option in drivers/firmware/efi/libstub/Makefile. When an
unknown flag is added to KBUILD_CFLAGS, clang will noisily warn that it
is ignoring the option like above, unlike gcc, who will just error.

$ echo "int main() { return 0; }" > tmp.c

$ clang -Wno-psabi tmp.c; echo $?
warning: unknown warning option '-Wno-psabi' [-Wunknown-warning-option]
1 warning generated.
0

$ gcc -Wsometimes-uninitialized tmp.c; echo $?
gcc: error: unrecognized command line option
‘-Wsometimes-uninitialized’; did you mean ‘-Wmaybe-uninitialized’?
1

For cc-option to work properly with clang and behave like gcc, -Werror
is needed, which was done in commit c3f0d0bc5b ("kbuild, LLVMLinux:
Add -Werror to cc-option to support clang").

$ clang -Werror -Wno-psabi tmp.c; echo $?
error: unknown warning option '-Wno-psabi'
[-Werror,-Wunknown-warning-option]
1

As a consequence of this, when an unknown flag is unconditionally added
to KBUILD_CFLAGS, it will cause cc-option to always fail and those flags
will never get added:

$ clang -Werror -Wno-psabi -fno-stack-protector tmp.c; echo $?
error: unknown warning option '-Wno-psabi'
[-Werror,-Wunknown-warning-option]
1

This can be seen when compiling the whole kernel as some warnings that
are normally disabled (see below) show up. The full list of flags
missing from drivers/firmware/efi/libstub are the following (gathered
from diffing .arm64-stub.o.cmd):

-fno-delete-null-pointer-checks
-Wno-address-of-packed-member
-Wframe-larger-than=2048
-Wno-unused-const-variable
-fno-strict-overflow
-fno-merge-all-constants
-fno-stack-check
-Werror=date-time
-Werror=incompatible-pointer-types
-ffreestanding
-fno-stack-protector

Use cc-disable-warning so that it gets disabled for GCC and does nothing
for Clang.

Fixes: ebcc5928c5 ("arm64: Silence gcc warnings about arch ABI drift")
Link: https://github.com/ClangBuiltLinux/linux/issues/511
Reported-by: Qian Cai <cai@lca.pw>
Acked-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-06-12 10:54:47 +01:00
Masahiro Yamada bd305f259c kconfig: make arch/*/configs/defconfig the default of KBUILD_DEFCONFIG
Until recently, if KBUILD_DEFCONFIG was not set by the arch Makefile,
the default path arch/*/defconfig was used.

The last users of the default are gone by the following commits:

- Commit f3e20ad67b ("s390: move arch/s390/defconfig to
  arch/s390/configs/defconfig")

- Commit 986a13769c ("alpha: move arch/alpha/defconfig to
  arch/alpha/configs/defconfig")

Let's set arch/*/configs/defconfig as a new default. This saves
KBUILD_DEFCONFIG for some architectures.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
2019-06-09 15:08:18 +09:00
Dave Martin ebcc5928c5 arm64: Silence gcc warnings about arch ABI drift
Since GCC 9, the compiler warns about evolution of the
platform-specific ABI, in particular relating for the marshaling of
certain structures involving bitfields.

The kernel is a standalone binary, and of course nobody would be
so stupid as to expose structs containing bitfields as function
arguments in ABI.  (Passing a pointer to such a struct, however
inadvisable, should be unaffected by this change.  perf and various
drivers rely on that.)

So these warnings do more harm than good: turn them off.

We may miss warnings about future ABI drift, but that's too bad.
Future ABI breaks of this class will have to be debugged and fixed
the traditional way unless the compiler evolves finer-grained
diagnostics.

Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2019-06-06 13:28:45 +01:00
Andrey Konovalov b2f557eae9 kasan, arm64: adjust shadow size for tag-based mode
Tag-based KASAN uses 1 shadow byte for 16 bytes of kernel memory, so it
requires 1/16th of the kernel virtual address space for the shadow memory.

This commit sets KASAN_SHADOW_SCALE_SHIFT to 4 when the tag-based KASAN
mode is enabled.

Link: http://lkml.kernel.org/r/308b6bd49f756bb5e533be93c6f085ba99b30339.1544099024.git.andreyknvl@google.com
Signed-off-by: Andrey Konovalov <andreyknvl@google.com>
Reviewed-by: Andrey Ryabinin <aryabinin@virtuozzo.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-12-28 12:11:43 -08:00
Ard Biesheuvel 0a1213fa74 arm64: enable per-task stack canaries
This enables the use of per-task stack canary values if GCC has
support for emitting the stack canary reference relative to the
value of sp_el0, which holds the task struct pointer in the arm64
kernel.

The $(eval) extends KBUILD_CFLAGS at the moment the make rule is
applied, which means asm-offsets.o (which we rely on for the offset
value) is built without the arguments, and everything built afterwards
has the options set.

Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-12-12 18:45:31 +00:00