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 <christophe.leroy@xxxxxx> Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxx> Signed-off-by: Daniel Axtens <dja@xxxxxxxxxx> --- Changes since v5: - rebase - riscv has now got support. - document s390 support while we're at it - clarify when kasan_vmalloc support is required --- 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 c652d740735d..012ef3d91d1f 100644 --- a/Documentation/dev-tools/kasan.rst +++ b/Documentation/dev-tools/kasan.rst @@ -22,7 +22,8 @@ global variables yet. 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. +riscv architectures. It is also supported on 32-bit powerpc kernels. Tag-based +KASAN is supported only on arm64. Usage ----- @@ -255,7 +256,9 @@ 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. -- 2.20.1
