KASAN support for RISC-V

KASAN is an important runtime memory debugging feature in linux kernel which can
detect use-after-free and out-of-bounds problems.

Changes in v2:
  - Remove the porting of memmove and exclude the check instead.
  - Fix some code noted by Christoph Hellwig

Changes in v3:
  - Update the KASAN documentation to mention that riscv is supported.

Changes in v4:
  - Correct the commit log
  - Fix the bug reported by Greentime Hu

Nick Hu (3):
  kasan: No KASAN's memmove check if archs don't have it.
  riscv: Add KASAN support
  kasan: Add riscv to KASAN documentation.

 Documentation/dev-tools/kasan.rst   |   4 +-
 arch/riscv/Kconfig                  |   1 +
 arch/riscv/include/asm/kasan.h      |  27 ++++++++
 arch/riscv/include/asm/pgtable-64.h |   5 ++
 arch/riscv/include/asm/string.h     |   9 +++
 arch/riscv/kernel/head.S            |   3 +
 arch/riscv/kernel/riscv_ksyms.c     |   2 +
 arch/riscv/kernel/setup.c           |   5 ++
 arch/riscv/kernel/vmlinux.lds.S     |   1 +
 arch/riscv/lib/memcpy.S             |   5 +-
 arch/riscv/lib/memset.S             |   5 +-
 arch/riscv/mm/Makefile              |   6 ++
 arch/riscv/mm/kasan_init.c          | 104 ++++++++++++++++++++++++++++
 mm/kasan/common.c                   |   2 +
 14 files changed, 173 insertions(+), 6 deletions(-)
 create mode 100644 arch/riscv/include/asm/kasan.h
 create mode 100644 arch/riscv/mm/kasan_init.c

-- 
2.17.0