From e178d670f251b6947d6be99c0014e9a57ad4f0e0 Mon Sep 17 00:00:00 2001 From: Nylon Chen Date: Sat, 16 Jan 2021 13:58:35 +0800 Subject: [PATCH] riscv/kasan: add KASAN_VMALLOC support It references to x86/s390 architecture. So, it doesn't map the early shadow page to cover VMALLOC space. Prepopulate top level page table for the range that would otherwise be empty. lower levels are filled dynamically upon memory allocation while booting. Signed-off-by: Nylon Chen Signed-off-by: Nick Hu Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 + arch/riscv/mm/kasan_init.c | 57 +++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 57 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 12ddd1f6bf70..4b9149f963d3 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -9,6 +9,19 @@ #include #include #include +#include + +static __init void *early_alloc(size_t size, int node) +{ + void *ptr = memblock_alloc_try_nid(size, size, + __pa(MAX_DMA_ADDRESS), MEMBLOCK_ALLOC_ACCESSIBLE, node); + + if (!ptr) + panic("%pS: Failed to allocate %zu bytes align=%zx nid=%d from=%llx\n", + __func__, size, size, node, (u64)__pa(MAX_DMA_ADDRESS)); + + return ptr; +} extern pgd_t early_pg_dir[PTRS_PER_PGD]; asmlinkage void __init kasan_early_init(void) @@ -83,6 +96,40 @@ static void __init populate(void *start, void *end) memset(start, 0, end - start); } +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); + unsigned long pfn; + int index; + void *p; + pud_t *pud_dir, *pud_k; + pgd_t *pgd_dir, *pgd_k; + p4d_t *p4d_dir, *p4d_k; + + while (vaddr < vend) { + index = pgd_index(vaddr); + pfn = csr_read(CSR_SATP) & SATP_PPN; + pgd_dir = (pgd_t *)pfn_to_virt(pfn) + index; + pgd_k = init_mm.pgd + index; + pgd_dir = pgd_offset_k(vaddr); + set_pgd(pgd_dir, *pgd_k); + + p4d_dir = p4d_offset(pgd_dir, vaddr); + p4d_k = p4d_offset(pgd_k, vaddr); + + vaddr = (vaddr + PUD_SIZE) & PUD_MASK; + pud_dir = pud_offset(p4d_dir, vaddr); + pud_k = pud_offset(p4d_k, vaddr); + + if (pud_present(*pud_dir)) { + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); + pud_populate(&init_mm, pud_dir, p); + } + vaddr += PAGE_SIZE; + } +} + void __init kasan_init(void) { phys_addr_t _start, _end; @@ -90,7 +137,15 @@ 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; -- 2.11.0