Commit Graph

11 Commits

Author SHA1 Message Date
Catalin Marinas
5d8505fd03 arm64: Fix the documented event stream frequency
It should be 10KHz, matching the ARCH_TIMER_EVT_STREAM_PERIOD_US of
100us.

Note that this is only a documentation bug.

Fixes: 611a7bc74e ("arm64: docs: describe ELF hwcaps")
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20210505132845.23698-1-catalin.marinas@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2021-05-05 18:34:28 +01:00
Bailu Lin
2472943cd4 Documentation: Chinese translation of Documentation/arm64/elf_hwcaps.rst
This is a Chinese translated version of
 Documentation/arm64/elf_hwcaps.rst

Signed-off-by: Bailu Lin <bailu.lin@vivo.com>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20201124023846.34826-1-bailu.lin@vivo.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2020-11-30 10:36:45 -07:00
Vincenzo Frascino
df9d7a22dd arm64: mte: Add Memory Tagging Extension documentation
Memory Tagging Extension (part of the ARMv8.5 Extensions) provides
a mechanism to detect the sources of memory related errors which
may be vulnerable to exploitation, including bounds violations,
use-after-free, use-after-return, use-out-of-scope and use before
initialization errors.

Add Memory Tagging Extension documentation for the arm64 linux
kernel support.

Signed-off-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Co-developed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Szabolcs Nagy <szabolcs.nagy@arm.com>
Cc: Will Deacon <will@kernel.org>
2020-09-04 12:46:07 +01:00
Dave Martin
8ef8f360cf arm64: Basic Branch Target Identification support
This patch adds the bare minimum required to expose the ARMv8.5
Branch Target Identification feature to userspace.

By itself, this does _not_ automatically enable BTI for any initial
executable pages mapped by execve().  This will come later, but for
now it should be possible to enable BTI manually on those pages by
using mprotect() from within the target process.

Other arches already using the generic mman.h are already using
0x10 for arch-specific prot flags, so we use that for PROT_BTI
here.

For consistency, signal handler entry points in BTI guarded pages
are required to be annotated as such, just like any other function.
This blocks a relatively minor attack vector, but comforming
userspace will have the annotations anyway, so we may as well
enforce them.

Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2020-03-16 17:19:48 +00:00
Will Deacon
bc20606594 Merge branch 'for-next/rng' into for-next/core
* for-next/rng: (2 commits)
  arm64: Use v8.5-RNG entropy for KASLR seed
  ...
2020-01-22 11:38:53 +00:00
Richard Henderson
1a50ec0b3b arm64: Implement archrandom.h for ARMv8.5-RNG
Expose the ID_AA64ISAR0.RNDR field to userspace, as the RNG system
registers are always available at EL0.

Implement arch_get_random_seed_long using RNDR.  Given that the
TRNG is likely to be a shared resource between cores, and VMs,
do not explicitly force re-seeding with RNDRRS.  In order to avoid
code complexity and potential issues with hetrogenous systems only
provide values after cpufeature has finalized the system capabilities.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
[Modified to only function after cpufeature has finalized the system
capabilities and move all the code into the header -- broonie]
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ardb@kernel.org>
[will: Advertise HWCAP via /proc/cpuinfo]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-22 09:54:18 +00:00
Steven Price
d4209d8b71 arm64: cpufeature: Export matrix and other features to userspace
Export the features introduced as part of ARMv8.6 exposed in the
ID_AA64ISAR1_EL1 and ID_AA64ZFR0_EL1 registers. This introduces the
Matrix features (ARMv8.2-I8MM, ARMv8.2-F64MM and ARMv8.2-F32MM) along
with BFloat16 (Armv8.2-BF16), speculation invalidation (SPECRES) and
Data Gathering Hint (ARMv8.0-DGH).

Signed-off-by: Julien Grall <julien.grall@arm.com>
[Added other features in those registers]
Signed-off-by: Steven Price <steven.price@arm.com>
[will: Don't advertise SPECRES to userspace]
Signed-off-by: Will Deacon <will@kernel.org>
2020-01-15 11:13:07 +00:00
Julien Grall
0f6e4c4016 docs/arm64: elf_hwcaps: Document HWCAP_SB
All the hardware capabilities but HWCAP_SB is not documented in
elf_hwcaps.rst. So document it.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:54:08 +01:00
Julien Grall
3a25e46c99 docs/arm64: elf_hwcaps: sort the HWCAP{, 2} documentation by ascending value
Part of the hardware capabilities documented in elf_hwcap.rst are
ordered following the definition in the header
arch/arm64/include/uapi/asm/hwcap.h but others seems to be documented
in random order.

To make easier to match against the definition in the header, they are
now sorted in the same order as they are defined in header. I.e.,
HWCAP first by ascending value, and then HWCAP2 in the similar fashion.

Acked-by: Will Deacon <will@kernel.org>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2019-10-14 10:54:08 +01:00
Linus Torvalds
e9a83bd232 It's been a relatively busy cycle for docs:
- A fair pile of RST conversions, many from Mauro.  These create more
    than the usual number of simple but annoying merge conflicts with other
    trees, unfortunately.  He has a lot more of these waiting on the wings
    that, I think, will go to you directly later on.
 
  - A new document on how to use merges and rebases in kernel repos, and one
    on Spectre vulnerabilities.
 
  - Various improvements to the build system, including automatic markup of
    function() references because some people, for reasons I will never
    understand, were of the opinion that :c:func:``function()`` is
    unattractive and not fun to type.
 
  - We now recommend using sphinx 1.7, but still support back to 1.4.
 
  - Lots of smaller improvements, warning fixes, typo fixes, etc.
 -----BEGIN PGP SIGNATURE-----
 
 iQFDBAABCAAtFiEEIw+MvkEiF49krdp9F0NaE2wMflgFAl0krAEPHGNvcmJldEBs
 d24ubmV0AAoJEBdDWhNsDH5Yg98H/AuLqO9LpOgUjF4LhyjxGPdzJkY9RExSJ7km
 gznyreLCZgFaJR+AY6YDsd4Jw6OJlPbu1YM/Qo3C3WrZVFVhgL/s2ebvBgCo50A8
 raAFd8jTf4/mGCHnAqRotAPQ3mETJUk315B66lBJ6Oc+YdpRhwXWq8ZW2bJxInFF
 3HDvoFgMf0KhLuMHUkkL0u3fxH1iA+KvDu8diPbJYFjOdOWENz/CV8wqdVkXRSEW
 DJxIq89h/7d+hIG3d1I7Nw+gibGsAdjSjKv4eRKauZs4Aoxd1Gpl62z0JNk6aT3m
 dtq4joLdwScydonXROD/Twn2jsu4xYTrPwVzChomElMowW/ZBBY=
 =D0eO
 -----END PGP SIGNATURE-----

Merge tag 'docs-5.3' of git://git.lwn.net/linux

Pull Documentation updates from Jonathan Corbet:
 "It's been a relatively busy cycle for docs:

   - A fair pile of RST conversions, many from Mauro. These create more
     than the usual number of simple but annoying merge conflicts with
     other trees, unfortunately. He has a lot more of these waiting on
     the wings that, I think, will go to you directly later on.

   - A new document on how to use merges and rebases in kernel repos,
     and one on Spectre vulnerabilities.

   - Various improvements to the build system, including automatic
     markup of function() references because some people, for reasons I
     will never understand, were of the opinion that
     :c:func:``function()`` is unattractive and not fun to type.

   - We now recommend using sphinx 1.7, but still support back to 1.4.

   - Lots of smaller improvements, warning fixes, typo fixes, etc"

* tag 'docs-5.3' of git://git.lwn.net/linux: (129 commits)
  docs: automarkup.py: ignore exceptions when seeking for xrefs
  docs: Move binderfs to admin-guide
  Disable Sphinx SmartyPants in HTML output
  doc: RCU callback locks need only _bh, not necessarily _irq
  docs: format kernel-parameters -- as code
  Doc : doc-guide : Fix a typo
  platform: x86: get rid of a non-existent document
  Add the RCU docs to the core-api manual
  Documentation: RCU: Add TOC tree hooks
  Documentation: RCU: Rename txt files to rst
  Documentation: RCU: Convert RCU UP systems to reST
  Documentation: RCU: Convert RCU linked list to reST
  Documentation: RCU: Convert RCU basic concepts to reST
  docs: filesystems: Remove uneeded .rst extension on toctables
  scripts/sphinx-pre-install: fix out-of-tree build
  docs: zh_CN: submitting-drivers.rst: Remove a duplicated Documentation/
  Documentation: PGP: update for newer HW devices
  Documentation: Add section about CPU vulnerabilities for Spectre
  Documentation: platform: Delete x86-laptop-drivers.txt
  docs: Note that :c:func: should no longer be used
  ...
2019-07-09 12:34:26 -07:00
Mauro Carvalho Chehab
b693d0b372 docs: arm64: convert docs to ReST and rename to .rst
The documentation is in a format that is very close to ReST format.

The conversion is actually:
  - add blank lines in order to identify paragraphs;
  - fixing tables markups;
  - adding some lists markups;
  - marking literal blocks;
  - adjust some title markups.

At its new index.rst, let's add a :orphan: while this is not linked to
the main index.rst file, in order to avoid build warnings.

Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-06-14 14:20:27 -06:00