[PATCH v4 0/2] arm64: Implement getrandom() in vDSO

[Adhemerval Zanella]

Implement stack-less ChaCha20 and wire it with the generic vDSO
getrandom code.  The first patch is Mark's fix to the alternatives
system in the vDSO, while the the second is the actual vDSO work.

Changes from v3:
- Use alternative_has_cap_likely instead of ALTERNATIVE.

Changes from v2:
- Refactor Makefile to use same flags for vgettimeofday and
  vgetrandom.
- Removed rodata usage and fixed BE on vgetrandom-chacha.S.

Changes from v1:
- Fixed style issues and typos.
- Added fallback for systems without NEON support.
- Avoid use of non-volatile vector registers in neon chacha20.
- Use c-getrandom-y for vgetrandom.c.
- Fixed TIMENS vdso_rnd_data access.

Adhemerval Zanella (1):
  arm64: vdso: wire up getrandom() vDSO implementation

Mark Rutland (1):
  arm64: alternative: make alternative_has_cap_likely() VDSO compatible

 arch/arm64/Kconfig                          |   1 +
 arch/arm64/include/asm/alternative-macros.h |   4 +
 arch/arm64/include/asm/mman.h               |   6 +-
 arch/arm64/include/asm/vdso.h               |   6 +
 arch/arm64/include/asm/vdso/getrandom.h     |  50 ++++++
 arch/arm64/include/asm/vdso/vsyscall.h      |  10 ++
 arch/arm64/kernel/vdso.c                    |   6 -
 arch/arm64/kernel/vdso/Makefile             |  25 ++-
 arch/arm64/kernel/vdso/vdso                 |   1 +
 arch/arm64/kernel/vdso/vdso.lds.S           |   4 +
 arch/arm64/kernel/vdso/vgetrandom-chacha.S  | 178 ++++++++++++++++++++
 arch/arm64/kernel/vdso/vgetrandom.c         |  15 ++
 tools/arch/arm64/vdso                       |   1 +
 tools/include/linux/compiler.h              |   4 +
 tools/testing/selftests/vDSO/Makefile       |   3 +-
 15 files changed, 298 insertions(+), 16 deletions(-)
 create mode 100644 arch/arm64/include/asm/vdso/getrandom.h
 create mode 120000 arch/arm64/kernel/vdso/vdso
 create mode 100644 arch/arm64/kernel/vdso/vgetrandom-chacha.S
 create mode 100644 arch/arm64/kernel/vdso/vgetrandom.c
 create mode 120000 tools/arch/arm64/vdso

-- 
2.43.0