[PATCH v10 4/6] kasan: Document support on 32-bit powerpc
From: Daniel Axtens <hidden>
Date: 2021-02-03 12:01:45
Also in:
linux-mm, lkml
Subsystem:
documentation, documentation process, kasan, the rest · Maintainers:
Jonathan Corbet, Andrey Ryabinin, Linus Torvalds
KASAN is supported on 32-bit powerpc and the docs should reflect this. Document s390 support while we're at it. Suggested-by: Christophe Leroy <redacted> Reviewed-by: Christophe Leroy <redacted> Signed-off-by: Daniel Axtens <redacted> --- Documentation/dev-tools/kasan.rst | 7 +++++-- Documentation/powerpc/kasan.txt | 12 ++++++++++++ 2 files changed, 17 insertions(+), 2 deletions(-) create mode 100644 Documentation/powerpc/kasan.txt
diff --git a/Documentation/dev-tools/kasan.rst b/Documentation/dev-tools/kasan.rst
index e022b7506e37..9cfc116cc6bf 100644
--- a/Documentation/dev-tools/kasan.rst
+++ b/Documentation/dev-tools/kasan.rst@@ -22,7 +22,8 @@ out-of-bounds accesses for global variables is only supported since Clang 11. Tag-based KASAN is only supported in Clang. Currently generic KASAN is supported for the x86_64, arm, arm64, xtensa, s390 -and riscv architectures, and tag-based KASAN modes are supported only for arm64. +and riscv architectures. It is also supported on 32-bit powerpc kernels. +Tag-based KASAN modes are supported only for arm64. Usage -----
@@ -332,7 +333,9 @@ CONFIG_KASAN_VMALLOC ~~~~~~~~~~~~~~~~~~~~ With ``CONFIG_KASAN_VMALLOC``, KASAN can cover vmalloc space at the -cost of greater memory usage. Currently this is only supported on x86. +cost of greater memory usage. Currently this supported on x86, s390 +and 32-bit powerpc. It is optional, except on 32-bit powerpc kernels +with module support, where it is required. This works by hooking into vmalloc and vmap, and dynamically allocating real shadow memory to back the mappings.
diff --git a/Documentation/powerpc/kasan.txt b/Documentation/powerpc/kasan.txt
new file mode 100644
index 000000000000..26bb0e8bb18c
--- /dev/null
+++ b/Documentation/powerpc/kasan.txt@@ -0,0 +1,12 @@ +KASAN is supported on powerpc on 32-bit only. + +32 bit support +============== + +KASAN is supported on both hash and nohash MMUs on 32-bit. + +The shadow area sits at the top of the kernel virtual memory space above the +fixmap area and occupies one eighth of the total kernel virtual memory space. + +Instrumentation of the vmalloc area is optional, unless built with modules, +in which case it is required.
--
2.27.0