Messages in this thread | | | Date | Mon, 29 Mar 2021 22:06:30 -0700 (PDT) | Subject | Re: [PATCH v3 2/2] riscv: Cleanup KASAN_VMALLOC support | From | Palmer Dabbelt <> |
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On Sat, 13 Mar 2021 00:45:05 PST (-0800), alex@ghiti.fr wrote: > When KASAN vmalloc region is populated, there is no userspace process and > the page table in use is swapper_pg_dir, so there is no need to read > SATP. Then we can use the same scheme used by kasan_populate_p*d > functions to go through the page table, which harmonizes the code. > > In addition, make use of set_pgd that goes through all unused page table > levels, contrary to p*d_populate functions, which makes this function work > whatever the number of page table levels. > > Signed-off-by: Alexandre Ghiti <alex@ghiti.fr> > Reviewed-by: Palmer Dabbelt <palmerdabbelt@google.com> > --- > arch/riscv/mm/kasan_init.c | 59 ++++++++++++-------------------------- > 1 file changed, 18 insertions(+), 41 deletions(-) > > diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c > index 57bf4ae09361..c16178918239 100644 > --- a/arch/riscv/mm/kasan_init.c > +++ b/arch/riscv/mm/kasan_init.c > @@ -11,18 +11,6 @@ > #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) > { > @@ -155,38 +143,27 @@ static void __init kasan_populate(void *start, void *end) > memset(start, KASAN_SHADOW_INIT, end - start); > } > > -void __init kasan_shallow_populate(void *start, void *end) > +static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end) > { > - unsigned long vaddr = (unsigned long)start & PAGE_MASK; > - unsigned long vend = PAGE_ALIGN((unsigned long)end); > - unsigned long pfn; > - int index; > + unsigned long next; > 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); > + 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)); > } > - vaddr += PAGE_SIZE; > - } > + } while (pgd_k++, vaddr = next, vaddr != end); > +} > + > +static 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(); > }
Thanks, this is on for-next.
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