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-rw-r--r--arch/riscv/mm/kasan_init.c474
1 files changed, 474 insertions, 0 deletions
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
new file mode 100644
index 000000000..e12267094
--- /dev/null
+++ b/arch/riscv/mm/kasan_init.c
@@ -0,0 +1,474 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2019 Andes Technology Corporation
+
+#include <linux/pfn.h>
+#include <linux/init_task.h>
+#include <linux/kasan.h>
+#include <linux/kernel.h>
+#include <linux/memblock.h>
+#include <linux/pgtable.h>
+#include <asm/tlbflush.h>
+#include <asm/fixmap.h>
+#include <asm/pgalloc.h>
+
+/*
+ * Kasan shadow region must lie at a fixed address across sv39, sv48 and sv57
+ * which is right before the kernel.
+ *
+ * For sv39, the region is aligned on PGDIR_SIZE so we only need to populate
+ * the page global directory with kasan_early_shadow_pmd.
+ *
+ * For sv48 and sv57, the region is not aligned on PGDIR_SIZE so the mapping
+ * must be divided as follows:
+ * - the first PGD entry, although incomplete, is populated with
+ * kasan_early_shadow_pud/p4d
+ * - the PGD entries in the middle are populated with kasan_early_shadow_pud/p4d
+ * - the last PGD entry is shared with the kernel mapping so populated at the
+ * lower levels pud/p4d
+ *
+ * In addition, when shallow populating a kasan region (for example vmalloc),
+ * this region may also not be aligned on PGDIR size, so we must go down to the
+ * pud level too.
+ */
+
+extern pgd_t early_pg_dir[PTRS_PER_PGD];
+
+static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ pte_t *ptep, *base_pte;
+
+ if (pmd_none(*pmd))
+ base_pte = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
+ else
+ base_pte = (pte_t *)pmd_page_vaddr(*pmd);
+
+ ptep = base_pte + pte_index(vaddr);
+
+ do {
+ if (pte_none(*ptep)) {
+ phys_addr = memblock_phys_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_pte(ptep, pfn_pte(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ }
+ } while (ptep++, vaddr += PAGE_SIZE, vaddr != end);
+
+ set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(base_pte)), PAGE_TABLE));
+}
+
+static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ pmd_t *pmdp, *base_pmd;
+ unsigned long next;
+
+ if (pud_none(*pud)) {
+ base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
+ } else {
+ base_pmd = (pmd_t *)pud_pgtable(*pud);
+ if (base_pmd == lm_alias(kasan_early_shadow_pmd))
+ base_pmd = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
+ }
+
+ pmdp = base_pmd + pmd_index(vaddr);
+
+ do {
+ next = pmd_addr_end(vaddr, end);
+
+ if (pmd_none(*pmdp) && IS_ALIGNED(vaddr, PMD_SIZE) && (next - vaddr) >= PMD_SIZE) {
+ phys_addr = memblock_phys_alloc(PMD_SIZE, PMD_SIZE);
+ if (phys_addr) {
+ set_pmd(pmdp, pfn_pmd(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ continue;
+ }
+ }
+
+ kasan_populate_pte(pmdp, vaddr, next);
+ } while (pmdp++, vaddr = next, vaddr != end);
+
+ /*
+ * Wait for the whole PGD to be populated before setting the PGD in
+ * the page table, otherwise, if we did set the PGD 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.
+ */
+ set_pud(pud, pfn_pud(PFN_DOWN(__pa(base_pmd)), PAGE_TABLE));
+}
+
+static void __init kasan_populate_pud(pgd_t *pgd,
+ unsigned long vaddr, unsigned long end,
+ bool early)
+{
+ phys_addr_t phys_addr;
+ pud_t *pudp, *base_pud;
+ 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_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);
+ memcpy(base_pud, (void *)kasan_early_shadow_pud,
+ sizeof(pud_t) * PTRS_PER_PUD);
+ } else {
+ base_pud = (pud_t *)pgd_page_vaddr(*pgd);
+ if (base_pud == lm_alias(kasan_early_shadow_pud)) {
+ base_pud = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
+ memcpy(base_pud, (void *)kasan_early_shadow_pud,
+ sizeof(pud_t) * PTRS_PER_PUD);
+ }
+ }
+
+ pudp = base_pud + pud_index(vaddr);
+
+ do {
+ next = pud_addr_end(vaddr, end);
+
+ if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
+ if (early) {
+ phys_addr = __pa(((uintptr_t)kasan_early_shadow_pmd));
+ set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ } else {
+ phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE);
+ if (phys_addr) {
+ set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ continue;
+ }
+ }
+ }
+
+ kasan_populate_pmd(pudp, vaddr, next);
+ } while (pudp++, vaddr = next, vaddr != end);
+
+ /*
+ * Wait for the whole PGD to be populated before setting the PGD in
+ * the page table, otherwise, if we did set the PGD 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_pud)), PAGE_TABLE));
+}
+
+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);
+ memcpy(base_p4d, (void *)kasan_early_shadow_p4d,
+ sizeof(p4d_t) * PTRS_PER_P4D);
+ }
+ }
+
+ 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))
+#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)))
+
+static void __init kasan_populate_pgd(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end,
+ bool early)
+{
+ phys_addr_t phys_addr;
+ unsigned long next;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+
+ if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE) {
+ if (early) {
+ phys_addr = __pa((uintptr_t)kasan_early_shadow_pgd_next);
+ set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ } else if (pgd_page_vaddr(*pgdp) ==
+ (unsigned long)lm_alias(kasan_early_shadow_pgd_next)) {
+ /*
+ * pgdp can't be none since kasan_early_init
+ * initialized all KASAN shadow region with
+ * kasan_early_shadow_pud: if this is still the
+ * case, that means we can try to allocate a
+ * hugepage as a replacement.
+ */
+ phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE);
+ if (phys_addr) {
+ set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ continue;
+ }
+ }
+ }
+
+ kasan_populate_pgd_next(pgdp, vaddr, next, early);
+ } while (pgdp++, vaddr = next, vaddr != end);
+}
+
+asmlinkage void __init kasan_early_init(void)
+{
+ uintptr_t i;
+
+ BUILD_BUG_ON(KASAN_SHADOW_OFFSET !=
+ KASAN_SHADOW_END - (1UL << (64 - KASAN_SHADOW_SCALE_SHIFT)));
+
+ for (i = 0; i < PTRS_PER_PTE; ++i)
+ set_pte(kasan_early_shadow_pte + i,
+ pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL));
+
+ for (i = 0; i < PTRS_PER_PMD; ++i)
+ set_pmd(kasan_early_shadow_pmd + i,
+ pfn_pmd(PFN_DOWN
+ (__pa((uintptr_t)kasan_early_shadow_pte)),
+ PAGE_TABLE));
+
+ if (pgtable_l4_enabled) {
+ for (i = 0; i < PTRS_PER_PUD; ++i)
+ set_pud(kasan_early_shadow_pud + i,
+ pfn_pud(PFN_DOWN
+ (__pa(((uintptr_t)kasan_early_shadow_pmd))),
+ 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);
+
+ local_flush_tlb_all();
+}
+
+void __init kasan_swapper_init(void)
+{
+ kasan_populate_pgd(pgd_offset_k(KASAN_SHADOW_START),
+ KASAN_SHADOW_START, KASAN_SHADOW_END, true);
+
+ local_flush_tlb_all();
+}
+
+static void __init kasan_populate(void *start, void *end)
+{
+ unsigned long vaddr = (unsigned long)start & PAGE_MASK;
+ unsigned long vend = PAGE_ALIGN((unsigned long)end);
+
+ kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend, false);
+
+ local_flush_tlb_all();
+ 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)
+{
+ unsigned long next;
+ pud_t *pudp, *base_pud;
+ pmd_t *base_pmd;
+ bool is_kasan_pmd;
+
+ base_pud = (pud_t *)pgd_page_vaddr(*pgdp);
+ pudp = base_pud + pud_index(vaddr);
+
+ do {
+ next = pud_addr_end(vaddr, end);
+ is_kasan_pmd = (pud_pgtable(*pudp) == lm_alias(kasan_early_shadow_pmd));
+
+ 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;
+ void *p;
+ pgd_t *pgd_k = pgd_offset_k(vaddr);
+ bool is_kasan_pgd_next;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+ is_kasan_pgd_next = (pgd_page_vaddr(*pgd_k) ==
+ (unsigned long)lm_alias(kasan_early_shadow_pgd_next));
+
+ if (is_kasan_pgd_next) {
+ p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ }
+
+ if (IS_ALIGNED(vaddr, PGDIR_SIZE) && (next - vaddr) >= PGDIR_SIZE)
+ continue;
+
+ 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);
+}
+
+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();
+}
+
+void __init kasan_init(void)
+{
+ phys_addr_t p_start, p_end;
+ u64 i;
+
+ 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));
+
+ /* Populate the linear mapping */
+ for_each_mem_range(i, &p_start, &p_end) {
+ void *start = (void *)__va(p_start);
+ void *end = (void *)__va(p_end);
+
+ if (start >= end)
+ break;
+
+ kasan_populate(kasan_mem_to_shadow(start), kasan_mem_to_shadow(end));
+ }
+
+ /* Populate kernel, BPF, modules mapping */
+ kasan_populate(kasan_mem_to_shadow((const void *)MODULES_VADDR),
+ kasan_mem_to_shadow((const void *)MODULES_VADDR + SZ_2G));
+
+ for (i = 0; i < PTRS_PER_PTE; i++)
+ set_pte(&kasan_early_shadow_pte[i],
+ mk_pte(virt_to_page(kasan_early_shadow_page),
+ __pgprot(_PAGE_PRESENT | _PAGE_READ |
+ _PAGE_ACCESSED)));
+
+ memset(kasan_early_shadow_page, KASAN_SHADOW_INIT, PAGE_SIZE);
+ init_task.kasan_depth = 0;
+}