Messages in this thread | | | Date | Thu, 14 Jan 2021 18:24:21 -0800 (PST) | Subject | Re: [PATCH 1/1] riscv/kasan: add KASAN_VMALLOC support | From | Palmer Dabbelt <> |
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On Tue, 12 Jan 2021 18:28:22 PST (-0800), nylon7@andestech.com wrote: > It's reference x86/s390 architecture. > > So, it's don'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 <nylon7@andestech.com> > Signed-off-by: Nick Hu <nickhu@andestech.com> > --- > arch/riscv/Kconfig | 1 + > arch/riscv/mm/kasan_init.c | 66 +++++++++++++++++++++++++++++++++++++- > 2 files changed, 66 insertions(+), 1 deletion(-) > > diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig > index 81b76d44725d..15a2c8088bbe 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..ee332513d728 100644 > --- a/arch/riscv/mm/kasan_init.c > +++ b/arch/riscv/mm/kasan_init.c > @@ -9,6 +9,19 @@ > #include <linux/pgtable.h> > #include <asm/tlbflush.h> > #include <asm/fixmap.h> > +#include <asm/pgalloc.h> > + > +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 +96,49 @@ 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; > + pmd_t *pmd_dir, *pmd_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); > + } > + > + pmd_dir = pmd_offset(pud_dir, vaddr); > + pmd_k = pmd_offset(pud_k,vaddr); > + set_pmd(pmd_dir, *pmd_k); > + if (pmd_present(*pmd_dir)) { > + p = early_alloc(PAGE_SIZE, NUMA_NO_NODE); > + pmd_populate(&init_mm, pmd_dir, p); > + } > + vaddr += PAGE_SIZE; > + } > +} > + > void __init kasan_init(void) > { > phys_addr_t _start, _end; > @@ -90,7 +146,15 @@ 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;
There are a bunch of checkpatch issues here.
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