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SubjectRe: [PATCH] riscv: Add KASAN_VMALLOC support
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Le 2/25/21 à 2:42 AM, Alexandre Ghiti a écrit :
> Populate the top-level of the kernel page table to implement KASAN_VMALLOC,
> lower levels are filled dynamically upon memory allocation at runtime.
>
> Co-developed-by: Nylon Chen <nylon7@andestech.com>
> Signed-off-by: Nylon Chen <nylon7@andestech.com>
> Co-developed-by: Nick Hu <nickhu@andestech.com>
> Signed-off-by: Nick Hu <nickhu@andestech.com>
> Signed-off-by: Alexandre Ghiti <alex@ghiti.fr>
> ---
> arch/riscv/Kconfig | 1 +
> arch/riscv/mm/kasan_init.c | 35 ++++++++++++++++++++++++++++++++++-
> 2 files changed, 35 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
> index 8eadd1cbd524..3832a537c5d6 100644
> --- a/arch/riscv/Kconfig
> +++ b/arch/riscv/Kconfig
> @@ -57,6 +57,7 @@ config RISCV
> select HAVE_ARCH_JUMP_LABEL
> select HAVE_ARCH_JUMP_LABEL_RELATIVE
> select HAVE_ARCH_KASAN if MMU && 64BIT
> + select HAVE_ARCH_KASAN_VMALLOC if MMU && 64BIT
> select HAVE_ARCH_KGDB
> select HAVE_ARCH_KGDB_QXFER_PKT
> select HAVE_ARCH_MMAP_RND_BITS if MMU
> diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
> index 719b6e4d6075..171569df4334 100644
> --- a/arch/riscv/mm/kasan_init.c
> +++ b/arch/riscv/mm/kasan_init.c
> @@ -142,6 +142,31 @@ static void __init kasan_populate(void *start, void *end)
> memset(start, KASAN_SHADOW_INIT, end - start);
> }
>
> +void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end)
> +{
> + unsigned long next;
> + void *p;
> + pgd_t *pgd_k = pgd_offset_k(vaddr);
> +
> + do {
> + next = pgd_addr_end(vaddr, end);
> + if (pgd_page_vaddr(*pgd_k) == (unsigned long)lm_alias(kasan_early_shadow_pmd)) {
> + p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
> + set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
> + }
> + } while (pgd_k++, vaddr = next, vaddr != end);
> +}
> +
> +void __init kasan_shallow_populate(void *start, void *end)
> +{
> + unsigned long vaddr = (unsigned long)start & PAGE_MASK;
> + unsigned long vend = PAGE_ALIGN((unsigned long)end);
> +
> + kasan_shallow_populate_pgd(vaddr, vend);
> +
> + local_flush_tlb_all();
> +}
> +
> void __init kasan_init(void)
> {
> phys_addr_t _start, _end;
> @@ -149,7 +174,15 @@ void __init kasan_init(void)
>
> kasan_populate_early_shadow((void *)KASAN_SHADOW_START,
> (void *)kasan_mem_to_shadow((void *)
> - VMALLOC_END));
> + VMEMMAP_END));
> + if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
> + kasan_shallow_populate(
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
> + else
> + kasan_populate_early_shadow(
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_START),
> + (void *)kasan_mem_to_shadow((void *)VMALLOC_END));
>
> for_each_mem_range(i, &_start, &_end) {
> void *start = (void *)_start;
>

Palmer, this commit should replace (if everyone agrees) Nylon and Nick's
Commit e178d670f251 ("riscv/kasan: add KASAN_VMALLOC support") that is
already in for-next.

Thanks,

Alex

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