Re: [PATCH v2 0/4] arm64: kasan: support CONFIG_KASAN_VMALLOC

[Andrey Konovalov <andreyknvl@google.com>]

On Sat, Jan 9, 2021 at 11:33 AM Lecopzer Chen <lecopzer@gmail.com> wrote:
>
> Linux supports KAsan for VMALLOC since commit 3c5c3cfb9ef4da9
> ("kasan: support backing vmalloc space with real shadow memory")
>
> Acroding to how x86 ported it [1], they early allocated p4d and pgd,
> but in arm64 I just simulate how KAsan supports MODULES_VADDR in arm64
> by not to populate the vmalloc area except for kimg address.
>
> Test environment:
>     4G and 8G Qemu virt,
>     39-bit VA + 4k PAGE_SIZE with 3-level page table,
>     test by lib/test_kasan.ko and lib/test_kasan_module.ko
>
> It also works in Kaslr with CONFIG_RANDOMIZE_MODULE_REGION_FULL
> and randomize module region inside vmalloc area.
>
>
> [1]: commit 0609ae011deb41c ("x86/kasan: support KASAN_VMALLOC")
>
> Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
> Acked-by: Andrey Konovalov <andreyknvl@google.com>
> Tested-by: Andrey Konovalov <andreyknvl@google.com>
>
>
> v2 -> v1
>         1. kasan_init.c tweak indent
>         2. change Kconfig depends only on HAVE_ARCH_KASAN
>         3. support randomized module region.
>
> v1:
> https://lore.kernel.org/lkml/20210103171137.153834-1-lecopzer@gmail.com/
>
> Lecopzer Chen (4):
>   arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC
>   arm64: kasan: abstract _text and _end to KERNEL_START/END
>   arm64: Kconfig: support CONFIG_KASAN_VMALLOC
>   arm64: kaslr: support randomized module area with KASAN_VMALLOC
>
>  arch/arm64/Kconfig         |  1 +
>  arch/arm64/kernel/kaslr.c  | 18 ++++++++++--------
>  arch/arm64/kernel/module.c | 16 +++++++++-------
>  arch/arm64/mm/kasan_init.c | 29 +++++++++++++++++++++--------
>  4 files changed, 41 insertions(+), 23 deletions(-)
>
> --
> 2.25.1
>

Hi Will,

Could you PTAL at the arm64 changes?

Thanks!