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    Subject[PATCH v2 1/4] arm64: kasan: don't populate vmalloc area for CONFIG_KASAN_VMALLOC
    Date
    Linux support KAsan for VMALLOC since commit 3c5c3cfb9ef4da9
    ("kasan: support backing vmalloc space with real shadow memory")

    Like how the MODULES_VADDR does now, just not to early populate
    the VMALLOC_START between VMALLOC_END.
    similarly, the kernel code mapping is now in the VMALLOC area and
    should keep these area populated.

    Signed-off-by: Lecopzer Chen <lecopzer.chen@mediatek.com>
    ---
    arch/arm64/mm/kasan_init.c | 23 ++++++++++++++++++-----
    1 file changed, 18 insertions(+), 5 deletions(-)

    diff --git a/arch/arm64/mm/kasan_init.c b/arch/arm64/mm/kasan_init.c
    index d8e66c78440e..39b218a64279 100644
    --- a/arch/arm64/mm/kasan_init.c
    +++ b/arch/arm64/mm/kasan_init.c
    @@ -214,6 +214,7 @@ static void __init kasan_init_shadow(void)
    {
    u64 kimg_shadow_start, kimg_shadow_end;
    u64 mod_shadow_start, mod_shadow_end;
    + u64 vmalloc_shadow_start, vmalloc_shadow_end;
    phys_addr_t pa_start, pa_end;
    u64 i;

    @@ -223,6 +224,9 @@ static void __init kasan_init_shadow(void)
    mod_shadow_start = (u64)kasan_mem_to_shadow((void *)MODULES_VADDR);
    mod_shadow_end = (u64)kasan_mem_to_shadow((void *)MODULES_END);

    + vmalloc_shadow_start = (u64)kasan_mem_to_shadow((void *)VMALLOC_START);
    + vmalloc_shadow_end = (u64)kasan_mem_to_shadow((void *)VMALLOC_END);
    +
    /*
    * We are going to perform proper setup of shadow memory.
    * At first we should unmap early shadow (clear_pgds() call below).
    @@ -241,12 +245,21 @@ static void __init kasan_init_shadow(void)

    kasan_populate_early_shadow(kasan_mem_to_shadow((void *)PAGE_END),
    (void *)mod_shadow_start);
    - kasan_populate_early_shadow((void *)kimg_shadow_end,
    - (void *)KASAN_SHADOW_END);
    + if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
    + kasan_populate_early_shadow((void *)vmalloc_shadow_end,
    + (void *)KASAN_SHADOW_END);
    + if (vmalloc_shadow_start > mod_shadow_end)
    + kasan_populate_early_shadow((void *)mod_shadow_end,
    + (void *)vmalloc_shadow_start);
    +
    + } else {
    + kasan_populate_early_shadow((void *)kimg_shadow_end,
    + (void *)KASAN_SHADOW_END);
    + if (kimg_shadow_start > mod_shadow_end)
    + kasan_populate_early_shadow((void *)mod_shadow_end,
    + (void *)kimg_shadow_start);
    + }

    - if (kimg_shadow_start > mod_shadow_end)
    - kasan_populate_early_shadow((void *)mod_shadow_end,
    - (void *)kimg_shadow_start);

    for_each_mem_range(i, &pa_start, &pa_end) {
    void *start = (void *)__phys_to_virt(pa_start);
    --
    2.25.1
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