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.
And finally, make sure the writes to swapper_pg_dir are visible using
an sfence.vma.
Signed-off-by: Alexandre Ghiti
---
arch/riscv/mm/kasan_init.c | 59 --
1 file changed, 19 insertions(+), 40 deletions(-)
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index e3d91f334b57..b0cee8d35938 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -11,18 +11,6 @@
#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)
{
@@ -155,38 +143,29 @@ 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);
- 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(_mm, pud_dir, p);
- }
- vaddr += PAGE_SIZE;
- }
+
+ kasan_shallow_populate_pgd(vaddr, vend);
+
+ local_flush_tlb_all();
}
void __init kasan_init(void)
--
2.20.1
