[PATCH 5/5 v13] ARM: Enable KASan for ARM

[Linus Walleij]

From: Andrey Ryabinin <ryabinin at virtuozzo.com>

This patch enables the kernel address sanitizer for ARM. XIP_KERNEL
has not been tested and is therefore not allowed for now.

Cc: Andrey Ryabinin <aryabinin at virtuozzo.com>
Cc: Alexander Potapenko <glider at google.com>
Cc: Dmitry Vyukov <dvyukov at google.com>
Cc: kasan-dev at googlegroups.com
Acked-by: Dmitry Vyukov <dvyukov at google.com>
Reviewed-by: Ard Biesheuvel <ardb at kernel.org>
Tested-by: Ard Biesheuvel <ardb at kernel.org> # QEMU/KVM/mach-virt/LPAE/8G
Signed-off-by: Abbott Liu <liuwenliang at huawei.com>
Signed-off-by: Florian Fainelli <f.fainelli at gmail.com>
Signed-off-by: Linus Walleij <linus.walleij at linaro.org>
---
ChangeLog v12->v13:
- Rebase on kernel v5.9-rc1
ChangeLog v11->v12:
- Resend with the other changes.
ChangeLog v10->v11:
- Resend with the other changes.
ChangeLog v9->v10:
- Rebase on v5.8-rc1
ChangeLog v8->v9:
- Fix the arch feature matrix for Arm to include KASan.
- Collect Ard's tags.
ChangeLog v7->v8:
- Moved the hacks to __ADDRESS_SANITIZE__ to the patch
  replacing the memory access functions.
- Moved the definition of KASAN_OFFSET out of this patch
  and to the patch that defines the virtual memory used by
  KASan.
---
 Documentation/dev-tools/kasan.rst                   | 4 ++--
 Documentation/features/debug/KASAN/arch-support.txt | 2 +-
 arch/arm/Kconfig                                    | 1 +
 3 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index 38fd5681fade..050dcd346144 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst
@@ -18,8 +18,8 @@ out-of-bounds accesses for global variables is only supported since Clang 11.
 
 Tag-based KASAN is only supported in Clang and requires version 7.0.0 or later.
 
-Currently generic KASAN is supported for the x86_64, arm64, xtensa, s390 and
-riscv architectures, and tag-based KASAN is supported only for arm64.
+Currently generic KASAN is supported for the x86_64, arm, arm64, xtensa, s390
+and riscv architectures, and tag-based KASAN is supported only for arm64.
 
 Usage
 -----
diff --git a/Documentation/features/debug/KASAN/arch-support.txt b/Documentation/features/debug/KASAN/arch-support.txt
index c3fe9b266e7b..b2288dc14b72 100644
--- a/Documentation/features/debug/KASAN/arch-support.txt
+++ b/Documentation/features/debug/KASAN/arch-support.txt
@@ -8,7 +8,7 @@
     -----------------------
     |       alpha: | TODO |
     |         arc: | TODO |
-    |         arm: | TODO |
+    |         arm: |  ok  |
     |       arm64: |  ok  |
     |         c6x: | TODO |
     |        csky: | TODO |
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 0489b8d07172..873bd26f5d43 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -66,6 +66,7 @@ config ARM
 	select HAVE_ARCH_BITREVERSE if (CPU_32v7M || CPU_32v7) && !CPU_32v6
 	select HAVE_ARCH_JUMP_LABEL if !XIP_KERNEL && !CPU_ENDIAN_BE32 && MMU
 	select HAVE_ARCH_KGDB if !CPU_ENDIAN_BE32 && MMU
+	select HAVE_ARCH_KASAN if MMU && !XIP_KERNEL
 	select HAVE_ARCH_MMAP_RND_BITS if MMU
 	select HAVE_ARCH_SECCOMP_FILTER if AEABI && !OABI_COMPAT
 	select HAVE_ARCH_THREAD_STRUCT_WHITELIST
-- 
2.26.2