Commit Graph

6705 Commits

Author SHA1 Message Date
Colin Ian King
c1c9142004 scripts/spelling.txt: add more spellings to spelling.txt
Here are some of the more common spelling mistakes and typos that I've
found while fixing up spelling mistakes in the kernel in the past few
months.

Link: https://lkml.kernel.org/r/20210514093655.8829-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:45 -07:00
Steven Rostedt (VMware)
d1b1f1e627 streamline_config.pl: add softtabstop=4 for vim users
The tab stop for Perl files is by default (at least in emacs) to be 4
spaces, where a tab is used for all 8 spaces.  Add a local variable
comment to make vim do the same by default, and this will help keep the
file consistent in the future when others edit it via vim and not emacs.

Link: https://lkml.kernel.org/r/20210322214032.293992979@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: "John (Warthog9) Hawley" <warthog9@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:45 -07:00
Steven Rostedt (VMware)
b83c8ba40c streamline_config.pl: make spacing consistent
Patch series "streamline_config.pl: Fix Perl spacing".

Talking with John Hawley about how vim and emacs deal with Perl files with
respect to tabs and spaces, I found that some of my Perl code in the
kernel had inconsistent spacing.  The way emacs handles Perl by default is
to use 4 spaces per indent, but make all 8 spaces into a single tab.  Vim
does not do this by default.  But if you add the vim variable control:

 # vim: softtabstop=4

to a perl file, it makes vim behave the same way as emacs.

The first patch is to change all 8 spaces into a single tab (mostly from
people editing the file with vim).  The next patch adds the softtabstop
variable to make vim act like emacs by default.

This patch (of 2):

As Perl code tends to have 4 space indentation, but uses tabs for every 8
spaces, make that consistent in the streamline_config.pl code.  Replace
all 8 spaces with a single tab.

Link: https://lkml.kernel.org/r/20210322214032.133596267@goodmis.org
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Cc: "John (Warthog9) Hawley" <warthog9@kernel.org>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-06-29 10:53:45 -07:00
Linus Torvalds
233a806b00 Merge tag 'docs-5.14' of git://git.lwn.net/linux
Pull documentation updates from Jonathan Corbet:
 "This was a reasonably active cycle for documentation; this includes:

   - Some kernel-doc cleanups. That script is still regex onslaught from
     hell, but it has gotten a little better.

   - Improvements to the checkpatch docs, which are also used by the
     tool itself.

   - A major update to the pathname lookup documentation.

   - Elimination of :doc: markup, since our automarkup magic can create
     references from filenames without all the extra noise.

   - The flurry of Chinese translation activity continues.

  Plus, of course, the usual collection of updates, typo fixes, and
  warning fixes"

* tag 'docs-5.14' of git://git.lwn.net/linux: (115 commits)
  docs: path-lookup: use bare function() rather than literals
  docs: path-lookup: update symlink description
  docs: path-lookup: update get_link() ->follow_link description
  docs: path-lookup: update WALK_GET, WALK_PUT desc
  docs: path-lookup: no get_link()
  docs: path-lookup: update i_op->put_link and cookie description
  docs: path-lookup: i_op->follow_link replaced with i_op->get_link
  docs: path-lookup: Add macro name to symlink limit description
  docs: path-lookup: remove filename_mountpoint
  docs: path-lookup: update do_last() part
  docs: path-lookup: update path_mountpoint() part
  docs: path-lookup: update path_to_nameidata() part
  docs: path-lookup: update follow_managed() part
  docs: Makefile: Use CONFIG_SHELL not SHELL
  docs: Take a little noise out of the build process
  docs: x86: avoid using ReST :doc:`foo` markup
  docs: virt: kvm: s390-pv-boot.rst: avoid using ReST :doc:`foo` markup
  docs: userspace-api: landlock.rst: avoid using ReST :doc:`foo` markup
  docs: trace: ftrace.rst: avoid using ReST :doc:`foo` markup
  docs: trace: coresight: coresight.rst: avoid using ReST :doc:`foo` markup
  ...
2021-06-28 16:53:05 -07:00
Linus Torvalds
9840cfcb97 Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
 "There's a reasonable amount here and the juicy details are all below.

  It's worth noting that the MTE/KASAN changes strayed outside of our
  usual directories due to core mm changes and some associated changes
  to some other architectures; Andrew asked for us to carry these [1]
  rather that take them via the -mm tree.

  Summary:

   - Optimise SVE switching for CPUs with 128-bit implementations.

   - Fix output format from SVE selftest.

   - Add support for versions v1.2 and 1.3 of the SMC calling
     convention.

   - Allow Pointer Authentication to be configured independently for
     kernel and userspace.

   - PMU driver cleanups for managing IRQ affinity and exposing event
     attributes via sysfs.

   - KASAN optimisations for both hardware tagging (MTE) and out-of-line
     software tagging implementations.

   - Relax frame record alignment requirements to facilitate 8-byte
     alignment with KASAN and Clang.

   - Cleanup of page-table definitions and removal of unused memory
     types.

   - Reduction of ARCH_DMA_MINALIGN back to 64 bytes.

   - Refactoring of our instruction decoding routines and addition of
     some missing encodings.

   - Move entry code moved into C and hardened against harmful compiler
     instrumentation.

   - Update booting requirements for the FEAT_HCX feature, added to v8.7
     of the architecture.

   - Fix resume from idle when pNMI is being used.

   - Additional CPU sanity checks for MTE and preparatory changes for
     systems where not all of the CPUs support 32-bit EL0.

   - Update our kernel string routines to the latest Cortex Strings
     implementation.

   - Big cleanup of our cache maintenance routines, which were
     confusingly named and inconsistent in their implementations.

   - Tweak linker flags so that GDB can understand vmlinux when using
     RELR relocations.

   - Boot path cleanups to enable early initialisation of per-cpu
     operations needed by KCSAN.

   - Non-critical fixes and miscellaneous cleanup"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (150 commits)
  arm64: tlb: fix the TTL value of tlb_get_level
  arm64: Restrict undef hook for cpufeature registers
  arm64/mm: Rename ARM64_SWAPPER_USES_SECTION_MAPS
  arm64: insn: avoid circular include dependency
  arm64: smp: Bump debugging information print down to KERN_DEBUG
  drivers/perf: fix the missed ida_simple_remove() in ddr_perf_probe()
  perf/arm-cmn: Fix invalid pointer when access dtc object sharing the same IRQ number
  arm64: suspend: Use cpuidle context helpers in cpu_suspend()
  PSCI: Use cpuidle context helpers in psci_cpu_suspend_enter()
  arm64: Convert cpu_do_idle() to using cpuidle context helpers
  arm64: Add cpuidle context save/restore helpers
  arm64: head: fix code comments in set_cpu_boot_mode_flag
  arm64: mm: drop unused __pa(__idmap_text_start)
  arm64: mm: fix the count comments in compute_indices
  arm64/mm: Fix ttbr0 values stored in struct thread_info for software-pan
  arm64: mm: Pass original fault address to handle_mm_fault()
  arm64/mm: Drop SECTION_[SHIFT|SIZE|MASK]
  arm64/mm: Use CONT_PMD_SHIFT for ARM64_MEMSTART_SHIFT
  arm64/mm: Drop SWAPPER_INIT_MAP_SIZE
  arm64: Conditionally configure PTR_AUTH key of the kernel.
  ...
2021-06-28 14:04:24 -07:00
Linus Torvalds
a15286c63d Merge tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:

 - Core locking & atomics:

     - Convert all architectures to ARCH_ATOMIC: move every architecture
       to ARCH_ATOMIC, then get rid of ARCH_ATOMIC and all the
       transitory facilities and #ifdefs.

       Much reduction in complexity from that series:

           63 files changed, 756 insertions(+), 4094 deletions(-)

     - Self-test enhancements

 - Futexes:

     - Add the new FUTEX_LOCK_PI2 ABI, which is a variant that doesn't
       set FLAGS_CLOCKRT (.e. uses CLOCK_MONOTONIC).

       [ The temptation to repurpose FUTEX_LOCK_PI's implicit setting of
         FLAGS_CLOCKRT & invert the flag's meaning to avoid having to
         introduce a new variant was resisted successfully. ]

     - Enhance futex self-tests

 - Lockdep:

     - Fix dependency path printouts

     - Optimize trace saving

     - Broaden & fix wait-context checks

 - Misc cleanups and fixes.

* tag 'locking-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (52 commits)
  locking/lockdep: Correct the description error for check_redundant()
  futex: Provide FUTEX_LOCK_PI2 to support clock selection
  futex: Prepare futex_lock_pi() for runtime clock selection
  lockdep/selftest: Remove wait-type RCU_CALLBACK tests
  lockdep/selftests: Fix selftests vs PROVE_RAW_LOCK_NESTING
  lockdep: Fix wait-type for empty stack
  locking/selftests: Add a selftest for check_irq_usage()
  lockding/lockdep: Avoid to find wrong lock dep path in check_irq_usage()
  locking/lockdep: Remove the unnecessary trace saving
  locking/lockdep: Fix the dep path printing for backwards BFS
  selftests: futex: Add futex compare requeue test
  selftests: futex: Add futex wait test
  seqlock: Remove trailing semicolon in macros
  locking/lockdep: Reduce LOCKDEP dependency list
  locking/lockdep,doc: Improve readability of the block matrix
  locking/atomics: atomic-instrumented: simplify ifdeffery
  locking/atomic: delete !ARCH_ATOMIC remnants
  locking/atomic: xtensa: move to ARCH_ATOMIC
  locking/atomic: sparc: move to ARCH_ATOMIC
  locking/atomic: sh: move to ARCH_ATOMIC
  ...
2021-06-28 11:45:29 -07:00
Linus Torvalds
b89c07dea1 Merge tags 'objtool-urgent-2021-06-28' and 'objtool-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fix and updates from Ingo Molnar:
 "An ELF format fix for a section flags mismatch bug that breaks kernel
  tooling such as kpatch-build.

  The biggest change in this cycle is the new code to handle and rewrite
  variable sized jump labels - which results in slightly tighter code
  generation in hot paths, through the use of short(er) NOPs.

  Also a number of cleanups and fixes, and a change to the generic
  include/linux/compiler.h to handle a s390 GCC quirk"

* tag 'objtool-urgent-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Don't make .altinstructions writable

* tag 'objtool-core-2021-06-28' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Improve reloc hash size guestimate
  instrumentation.h: Avoid using inline asm operand modifiers
  compiler.h: Avoid using inline asm operand modifiers
  kbuild: Fix objtool dependency for 'OBJECT_FILES_NON_STANDARD_<obj> := n'
  objtool: Reflow handle_jump_alt()
  jump_label/x86: Remove unused JUMP_LABEL_NOP_SIZE
  jump_label, x86: Allow short NOPs
  objtool: Provide stats for jump_labels
  objtool: Rewrite jump_label instructions
  objtool: Decode jump_entry::key addend
  jump_label, x86: Emit short JMP
  jump_label: Free jump_entry::key bit1 for build use
  jump_label, x86: Add variable length patching support
  jump_label, x86: Introduce jump_entry_size()
  jump_label, x86: Improve error when we fail expected text
  jump_label, x86: Factor out the __jump_table generation
  jump_label, x86: Strip ASM jump_label support
  x86, objtool: Dont exclude arch/x86/realmode/
  objtool: Rewrite hashtable sizing
2021-06-28 11:35:55 -07:00
Nathan Chancellor
e2bc3e91d9 scripts/min-tool-version.sh: Raise minimum clang version to 13.0.0 for s390
clang versions prior to the current development version of 13.0.0 cannot
compile s390 after commit 3abbdfde5a65 ("s390/bitops: use register pair
instead of register asm") and the s390 maintainers do not intend to work
around this in the kernel. Codify this in scripts/min-tool-version.sh
similar to arm64 with GCC 5.1.0 so that there are no reports of broken
builds.

[hca@linux.ibm.com: breaking compatibility with older clang compilers
 is intended to finally make use of a feature which allows the
 compiler to allocate even/odd register pairs. This is possible since
 a very long time with gcc, but only since llvm-project commit
 d058262b1471 ("[SystemZ] Support i128 inline asm operands.") with
 clang. Using that feature allows to get rid of error prone register
 asm statements, of which the above named kernel commit is only the
 first of a larger not yet complete series.]

Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Acked-by: Nick Desaulniers <ndesaulniers@google.com>
Acked-by: Masahiro Yamada <masahiroy@kernel.org>
Link: https://lore.kernel.org/r/20210617193139.856957-1-nathan@kernel.org
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
2021-06-28 11:18:28 +02:00
Will Deacon
2c9bd9d806 Merge branch 'for-next/kasan' into for-next/core
Optimise out-of-line KASAN checking when using software tagging.

* for-next/kasan:
  kasan: arm64: support specialized outlined tag mismatch checks
2021-06-24 14:04:00 +01:00
Keith Busch
5e52344627 coccinelle: api: remove kobj_to_dev.cocci script
Using kobj_to_dev() instead of container_of() is not universally
accepted among maintainers as an improvement. The warning leads to
repeated patch submissions that won't be accepted. Remove the script.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Denis Efremov <efremov@linux.com>
Cc: Julia Lawall <Julia.Lawall@inria.fr>
Signed-off-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Julia Lawall <Julia.Lawall@inria.fr>
Acked-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Denis Efremov <efremov@linux.com>
2021-06-21 20:45:49 +02:00
Peter Zijlstra
fb780761e7 recordmcount: Correct st_shndx handling
One should only use st_shndx when >SHN_UNDEF and <SHN_LORESERVE. When
SHN_XINDEX, then use .symtab_shndx. Otherwise use 0.

This handles the case: st_shndx >= SHN_LORESERVE && st_shndx != SHN_XINDEX.

Link: https://lore.kernel.org/lkml/20210607023839.26387-1-mark-pk.tsai@mediatek.com/
Link: https://lkml.kernel.org/r/20210616154126.2794-1-mark-pk.tsai@mediatek.com

Reported-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Tested-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[handle endianness of sym->st_shndx]
Signed-off-by: Mark-PK Tsai <mark-pk.tsai@mediatek.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2021-06-18 09:09:17 -04:00
Matthias Maennich
a979522a1a kbuild: mkcompile_h: consider timestamp if KBUILD_BUILD_TIMESTAMP is set
To avoid unnecessary recompilations, mkcompile_h does not regenerate
compile.h if just the timestamp changed.
Though, if KBUILD_BUILD_TIMESTAMP is set, an explicit timestamp for the
build was requested, in which case we should not ignore it.

If a user follows the documentation for reproducible builds [1] and
defines KBUILD_BUILD_TIMESTAMP as the git commit timestamp, a clean
build will have the correct timestamp. A subsequent cherry-pick (or
amend) changes the commit timestamp and if an incremental build is done
with a different KBUILD_BUILD_TIMESTAMP now, that new value is not taken
into consideration. But it should for reproducibility.

Hence, whenever KBUILD_BUILD_TIMESTAMP is explicitly set, do not ignore
UTS_VERSION when making a decision about whether the regenerated version
of compile.h should be moved into place.

[1] https://www.kernel.org/doc/html/latest/kbuild/reproducible-builds.html

Signed-off-by: Matthias Maennich <maennich@google.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-06-17 10:01:12 +09:00
Mark Brown
4a6795933a kbuild: modpost: Explicitly warn about unprototyped symbols
One common cause of modpost version generation failures is a failure to
prototype exported assembly functions - the tooling requires this for
exported functions even if they are not and should not be called from C
code in order to do the version mangling for symbols. Unfortunately the
error message is currently rather abstruse, simply saying that "version
generation failed" and even diving into the code doesn't directly show
what's going on since there's several steps between the problem and it
being observed.

Provide an explicit hint as to the likely cause of a version generation
failure to help anyone who runs into this in future more readily diagnose
and fix the problem.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-06-17 10:01:05 +09:00
Nick Desaulniers
27f2a4db76 Makefile: fix GDB warning with CONFIG_RELR
GDB produces the following warning when debugging kernels built with
CONFIG_RELR:

BFD: /android0/linux-next/vmlinux: unknown type [0x13] section `.relr.dyn'

when loading a kernel built with CONFIG_RELR into GDB. It can also
prevent debugging symbols using such relocations.

Peter sugguests:
  [That flag] means that lld will use dynamic tags and section type
  numbers in the OS-specific range rather than the generic range. The
  kernel itself doesn't care about these numbers; it determines the
  location of the RELR section using symbols defined by a linker script.

Link: https://github.com/ClangBuiltLinux/linux/issues/1057
Suggested-by: Peter Collingbourne <pcc@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Signed-off-by: Nick Desaulniers <ndesaulniers@google.com>
Link: https://lore.kernel.org/r/20210522012626.2811297-1-ndesaulniers@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-06-08 13:09:34 +01:00
Masahiro Yamada
43ac711053 kconfig: constify long_opts
getopt_long() does not modify the long_opts structure.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2021-06-05 23:49:46 +09:00
Rob Herring
709dedfdf3 documentation-file-ref-check: Make git check work for multiple working directories
With multiple git working directories, '.git' may also be a text file
linking to the actual git tree instead of a directory.

Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Tested-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lore.kernel.org/r/20210603012806.331132-1-robh@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-04 11:20:52 -06:00
Mauro Carvalho Chehab
a5f785f102 scripts: sphinx-pre-install: fix the need of virtenv packages
The pip packages are only needed when the distro-provided
Sphinx version is not good enough.

Don't recommend installing it if not needed.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/04ce53b77b37f1e495c3abc39c2d3dc407895dc0.1621949137.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-01 16:29:30 -06:00
Mauro Carvalho Chehab
e50899122f scripts: sphinx-pre-install: rework the sphinx install logic
The sphinx-pre-install supports installing sphinx via a virtual
environment using pip/pypi or directly from the distribution's
package, when --no-virtualenv is used.

However, even when --no-virtualenv, the current logic is
still recomending to install a virtual env, due to a regression.

It turns that the logic there is complex, as it depends on
several different conditions.

Split the code which recommends Sphinx on two separate
functions, in order to clean up the code.

Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Link: https://lore.kernel.org/r/9dedaec201803017b7a7dc24a074f3a4f040b72a.1621949137.git.mchehab+huawei@kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2021-06-01 16:29:30 -06:00
Javier Martinez Canillas
ff2e6efda0 kbuild: Quote OBJCOPY var to avoid a pahole call break the build
The ccache tool can be used to speed up cross-compilation, by calling the
compiler and binutils through ccache. For example, following should work:

    $ export ARCH=arm64 CROSS_COMPILE="ccache aarch64-linux-gnu-"

    $ make M=drivers/gpu/drm/rockchip/

but pahole fails to extract the BTF info from DWARF, breaking the build:

      CC [M]  drivers/gpu/drm/rockchip//rockchipdrm.mod.o
      LD [M]  drivers/gpu/drm/rockchip//rockchipdrm.ko
      BTF [M] drivers/gpu/drm/rockchip//rockchipdrm.ko
    aarch64-linux-gnu-objcopy: invalid option -- 'J'
    Usage: aarch64-linux-gnu-objcopy [option(s)] in-file [out-file]
     Copies a binary file, possibly transforming it in the process
    ...
    make[1]: *** [scripts/Makefile.modpost:156: __modpost] Error 2
    make: *** [Makefile:1866: modules] Error 2

this fails because OBJCOPY is set to "ccache aarch64-linux-gnu-copy" and
later pahole is executed with the following command line:

    LLVM_OBJCOPY=$(OBJCOPY) $(PAHOLE) -J --btf_base vmlinux $@

which gets expanded to:

    LLVM_OBJCOPY=ccache aarch64-linux-gnu-objcopy pahole -J ...

instead of:

    LLVM_OBJCOPY="ccache aarch64-linux-gnu-objcopy" pahole -J ...

Fixes: 5f9ae91f7c ("kbuild: Build kernel module BTFs if BTF is enabled and pahole supports it")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Link: https://lore.kernel.org/bpf/20210526215228.3729875-1-javierm@redhat.com
2021-05-27 11:32:56 -07:00
Peter Collingbourne
1cbdf60bd1 kasan: arm64: support specialized outlined tag mismatch checks
By using outlined checks we can achieve a significant code size
improvement by moving the tag-based ASAN checks into separate
functions. Unlike the existing CONFIG_KASAN_OUTLINE mode these
functions have a custom calling convention that preserves most
registers and is specialized to the register containing the address
and the type of access, and as a result we can eliminate the code
size and performance overhead of a standard calling convention such
as AAPCS for these functions.

This change depends on a separate series of changes to Clang [1] to
support outlined checks in the kernel, although the change works fine
without them (we just don't get outlined checks). This is because the
flag -mllvm -hwasan-inline-all-checks=0 has no effect until the Clang
changes land. The flag was introduced in the Clang 9.0 timeframe as
part of the support for outlined checks in userspace and because our
minimum Clang version is 10.0 we can pass it unconditionally.

Outlined checks require a new runtime function with a custom calling
convention. Add this function to arch/arm64/lib.

I measured the code size of defconfig + tag-based KASAN, as well
as boot time (i.e. time to init launch) on a DragonBoard 845c with
an Android arm64 GKI kernel. The results are below:

                               code size    boot time
CONFIG_KASAN_INLINE=y before    92824064      6.18s
CONFIG_KASAN_INLINE=y after     38822400      6.65s
CONFIG_KASAN_OUTLINE=y          39215616     11.48s

We can see straight away that specialized outlined checks beat the
existing CONFIG_KASAN_OUTLINE=y on both code size and boot time
for tag-based ASAN.

As for the comparison between CONFIG_KASAN_INLINE=y before and after
we saw similar performance numbers in userspace [2] and decided
that since the performance overhead is minimal compared to the
overhead of tag-based ASAN itself as well as compared to the code
size improvements we would just replace the inlined checks with the
specialized outlined checks without the option to select between them,
and that is what I have implemented in this patch.

Signed-off-by: Peter Collingbourne <pcc@google.com>
Acked-by: Andrey Konovalov <andreyknvl@gmail.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Link: https://linux-review.googlesource.com/id/I1a30036c70ab3c3ee78d75ed9b87ef7cdc3fdb76
Link: [1] https://reviews.llvm.org/D90426
Link: [2] https://reviews.llvm.org/D56954
Link: https://lore.kernel.org/r/20210526174927.2477847-3-pcc@google.com
Signed-off-by: Will Deacon <will@kernel.org>
2021-05-26 23:31:26 +01:00
Masahiro Yamada
042da426f8 scripts/setlocalversion: simplify the short version part
Reduce the indentation.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
2021-05-27 04:01:51 +09:00
Masahiro Yamada
630ff0faf8 scripts/setlocalversion: factor out 12-chars hash construction
Both of if and else parts append exactly 12 hex chars, but in
different ways.

Factor out the else part because we need to support it without relying
on git-describe. Remove the --abbrev=12 option since we do not use the
hash from git-describe anyway.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
2021-05-27 04:01:51 +09:00
Masahiro Yamada
ffaf62a805 scripts/setlocalversion: add more comments to -dirty flag detection
This script stumbled on the read-only source tree over again:

 - a2bb90a08c ("kbuild: fix delay in setlocalversion on readonly
   source")

 - cdf2bc632e ("scripts/setlocalversion on write-protected source
   tree")

 - 8ef14c2c41 ("Revert "scripts/setlocalversion: git: Make -dirty
   check more robust"")

 - ff64dd4857 ("scripts/setlocalversion: Improve -dirty check with
   git-status --no-optional-locks")

Add comments to clarify that this script should never ever try to write
to the source tree.

'git describe --dirty' might look as a simple solution for appending
the -dirty string, but we cannot use it because it creates the
.git/index.lock file.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
2021-05-27 04:01:51 +09:00
Masahiro Yamada
a2be76a352 scripts/setlocalversion: remove workaround for old make-kpkg
This reverts commit b052ce4c84 ("kbuild: fix false positive -dirty
tag caused by make-kpkg").

If I understand correctly, this problem occurred in very old versions
of make-kpkg. When I tried a newer version, make-kpkg did not touch
scripts/package/Makefile.

Anyway, Debian uses 'make deb-pkg' instead of make-kpkg these days.

Debian handbook [1] mentions it as "the good old days":

 "CULTURE The good old days of kernel-package

  Before the Linux build system gained the ability to build proper
  Debian packages, the recommended way to build such packages was to
  use make-kpkg from the kernel-package package."

[1]: https://debian-handbook.info/browse/stable/sect.kernel-compilation.html

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
2021-05-27 04:01:51 +09:00
Masahiro Yamada
2a73cce2da scripts/setlocalversion: remove mercurial, svn and git-svn supports
The mercurial, svn, git-svn supports were added by the following commits:

 - 3dce174cfc ("kbuild: support mercurial in setlocalversion")

 - ba3d05fb63 ("kbuild: add svn revision information to setlocalversion")

 - ff80aa97c9 ("setlocalversion: add git-svn support")

They did not explain why they are useful for the kernel source tree.
Let's revert all of them, and see if somebody will complain about it.

Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Nico Schottelius <nico-linuxsetlocalversion@schottelius.org>
2021-05-27 04:01:51 +09:00