[PATCH v2 4/4] riscv: mm: Support kasan for sv57
panqinglin2020 at iscas.ac.cn
panqinglin2020 at iscas.ac.cn
Wed Jan 26 18:48:44 PST 2022
From: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
This patchset add kasan_populate and kasan_shallow_populate for sv57,
and is tested on both qemu and unmatched with CONFIG_KASAN and
CONFIG_KASAN_VMALLOC on.
Signed-off-by: Qinglin Pan <panqinglin2020 at iscas.ac.cn>
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index f61f7ca6fe0f..3c99b24c9adf 100644
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -111,6 +111,8 @@ static void __init kasan_populate_pud(pgd_t *pgd,
* pt_ops facility.
*/
base_pud = pt_ops.get_pud_virt(pfn_to_phys(_pgd_pfn(*pgd)));
+ } else if (pgd_none(*pgd)) {
+ base_pud = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
} else {
base_pud = (pud_t *)pgd_page_vaddr(*pgd);
if (base_pud == lm_alias(kasan_early_shadow_pud))
@@ -149,13 +151,72 @@ static void __init kasan_populate_pud(pgd_t *pgd,
set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_pud)), PAGE_TABLE));
}
-#define kasan_early_shadow_pgd_next (pgtable_l4_enabled ? \
+static void __init kasan_populate_p4d(pgd_t *pgd,
+ unsigned long vaddr, unsigned long end,
+ bool early)
+{
+ phys_addr_t phys_addr;
+ p4d_t *p4dp, *base_p4d;
+ unsigned long next;
+
+ if (early) {
+ /*
+ * We can't use pgd_page_vaddr here as it would return a linear
+ * mapping address but it is not mapped yet, but when populating
+ * early_pg_dir, we need the physical address and when populating
+ * swapper_pg_dir, we need the kernel virtual address so use
+ * pt_ops facility.
+ */
+ base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgd)));
+ } else {
+ base_p4d = (p4d_t *)pgd_page_vaddr(*pgd);
+ if (base_p4d == lm_alias(kasan_early_shadow_p4d))
+ base_p4d = memblock_alloc(PTRS_PER_PUD * sizeof(p4d_t), PAGE_SIZE);
+ }
+
+ p4dp = base_p4d + p4d_index(vaddr);
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+
+ if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) {
+ if (early) {
+ phys_addr = __pa(((uintptr_t)kasan_early_shadow_pud));
+ set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ } else {
+ phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE);
+ if (phys_addr) {
+ set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ continue;
+ }
+ }
+ }
+
+ kasan_populate_pud((pgd_t *)p4dp, vaddr, next, early);
+ } while (p4dp++, vaddr = next, vaddr != end);
+
+ /*
+ * Wait for the whole P4D to be populated before setting the P4D in
+ * the page table, otherwise, if we did set the P4D before populating
+ * it entirely, memblock could allocate a page at a physical address
+ * where KASAN is not populated yet and then we'd get a page fault.
+ */
+ if (!early)
+ set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(base_p4d)), PAGE_TABLE));
+}
+
+#define kasan_early_shadow_pgd_next (pgtable_l5_enabled ? \
+ (uintptr_t)kasan_early_shadow_p4d : \
+ (pgtable_l4_enabled ? \
(uintptr_t)kasan_early_shadow_pud : \
- (uintptr_t)kasan_early_shadow_pmd)
+ (uintptr_t)kasan_early_shadow_pmd))
#define kasan_populate_pgd_next(pgdp, vaddr, next, early) \
+ (pgtable_l5_enabled ? \
+ kasan_populate_p4d(pgdp, vaddr, next, early) : \
(pgtable_l4_enabled ? \
kasan_populate_pud(pgdp, vaddr, next, early) : \
- kasan_populate_pmd((pud_t *)pgdp, vaddr, next))
+ kasan_populate_pmd((pud_t *)pgdp, vaddr, next)))
static void __init kasan_populate_pgd(pgd_t *pgdp,
unsigned long vaddr, unsigned long end,
@@ -219,6 +280,14 @@ asmlinkage void __init kasan_early_init(void)
PAGE_TABLE));
}
+ if (pgtable_l5_enabled) {
+ for (i = 0; i < PTRS_PER_P4D; ++i)
+ set_p4d(kasan_early_shadow_p4d + i,
+ pfn_p4d(PFN_DOWN
+ (__pa(((uintptr_t)kasan_early_shadow_pud))),
+ PAGE_TABLE));
+ }
+
kasan_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START),
KASAN_SHADOW_START, KASAN_SHADOW_END, true);
@@ -244,9 +313,27 @@ static void __init kasan_populate(void *start, void *end)
memset(start, KASAN_SHADOW_INIT, end - start);
}
+static void __init kasan_shallow_populate_pmd(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ unsigned long next;
+ pmd_t *pmdp, *base_pmd;
+ bool is_kasan_pte;
+
+ base_pmd = (pmd_t *)pgd_page_vaddr(*pgdp);
+ pmdp = base_pmd + pmd_index(vaddr);
+
+ do {
+ next = pmd_addr_end(vaddr, end);
+ is_kasan_pte = (pmd_pgtable(*pmdp) == lm_alias(kasan_early_shadow_pte));
+
+ if (is_kasan_pte)
+ pmd_clear(pmdp);
+ } while (pmdp++, vaddr = next, vaddr != end);
+}
+
static void __init kasan_shallow_populate_pud(pgd_t *pgdp,
- unsigned long vaddr, unsigned long end,
- bool kasan_populate)
+ unsigned long vaddr, unsigned long end)
{
unsigned long next;
pud_t *pudp, *base_pud;
@@ -256,21 +343,60 @@ static void __init kasan_shallow_populate_pud(pgd_t *pgdp,
base_pud = (pud_t *)pgd_page_vaddr(*pgdp);
pudp = base_pud + pud_index(vaddr);
- if (kasan_populate)
- memcpy(base_pud, (void *)kasan_early_shadow_pgd_next,
- sizeof(pud_t) * PTRS_PER_PUD);
-
do {
next = pud_addr_end(vaddr, end);
is_kasan_pmd = (pud_pgtable(*pudp) == lm_alias(kasan_early_shadow_pmd));
- if (is_kasan_pmd) {
- base_pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
- set_pud(pudp, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE));
- }
+ if (!is_kasan_pmd)
+ continue;
+
+ base_pmd = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_pud(pudp, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE));
+
+ if (IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE)
+ continue;
+
+ memcpy(base_pmd, (void *)kasan_early_shadow_pmd, PAGE_SIZE);
+ kasan_shallow_populate_pmd((pgd_t *)pudp, vaddr, next);
} while (pudp++, vaddr = next, vaddr != end);
}
+static void __init kasan_shallow_populate_p4d(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ unsigned long next;
+ p4d_t *p4dp, *base_p4d;
+ pud_t *base_pud;
+ bool is_kasan_pud;
+
+ base_p4d = (p4d_t *)pgd_page_vaddr(*pgdp);
+ p4dp = base_p4d + p4d_index(vaddr);
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+ is_kasan_pud = (p4d_pgtable(*p4dp) == lm_alias(kasan_early_shadow_pud));
+
+ if (!is_kasan_pud)
+ continue;
+
+ base_pud = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_p4d(p4dp, pfn_p4d(PFN_DOWN(__pa(base_pud)), PAGE_TABLE));
+
+ if (IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE)
+ continue;
+
+ memcpy(base_pud, (void *)kasan_early_shadow_pud, PAGE_SIZE);
+ kasan_shallow_populate_pud((pgd_t *)p4dp, vaddr, next);
+ } while (p4dp++, vaddr = next, vaddr != end);
+}
+
+#define kasan_shallow_populate_pgd_next(pgdp, vaddr, next) \
+ (pgtable_l5_enabled ? \
+ kasan_shallow_populate_p4d(pgdp, vaddr, next) : \
+ (pgtable_l4_enabled ? \
+ kasan_shallow_populate_pud(pgdp, vaddr, next) : \
+ kasan_shallow_populate_pmd(pgdp, vaddr, next)))
+
static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long end)
{
unsigned long next;
@@ -291,7 +417,8 @@ static void __init kasan_shallow_populate_pgd(unsigned long vaddr, unsigned long
if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE)
continue;
- kasan_shallow_populate_pud(pgd_k, vaddr, next, is_kasan_pgd_next);
+ memcpy(p, (void *)kasan_early_shadow_pgd_next, PAGE_SIZE);
+ kasan_shallow_populate_pgd_next(pgd_k, vaddr, next);
} while (pgd_k++, vaddr = next, vaddr != end);
}
--
2.34.1
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