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

Lecopzer Chen
2021-01-09T10:34:38Z

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(-)

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2.25.1