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-rw-r--r--arch/riscv/mm/kasan_init.c525
1 files changed, 525 insertions, 0 deletions
diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
new file mode 100644
index 0000000000..5e39dcf23f
--- /dev/null
+++ b/arch/riscv/mm/kasan_init.c
@@ -0,0 +1,525 @@
+// 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 start is aligned on PGDIR_SIZE whereas the end
+ * region is not and then we have to go down to the PUD level.
+ */
+
+static pgd_t tmp_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+static p4d_t tmp_p4d[PTRS_PER_P4D] __page_aligned_bss;
+static pud_t tmp_pud[PTRS_PER_PUD] __page_aligned_bss;
+
+static void __init kasan_populate_pte(pmd_t *pmd, unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ pte_t *ptep, *p;
+
+ if (pmd_none(*pmd)) {
+ p = memblock_alloc(PTRS_PER_PTE * sizeof(pte_t), PAGE_SIZE);
+ set_pmd(pmd, pfn_pmd(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ }
+
+ ptep = pte_offset_kernel(pmd, 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));
+ memset(__va(phys_addr), KASAN_SHADOW_INIT, PAGE_SIZE);
+ }
+ } while (ptep++, vaddr += PAGE_SIZE, vaddr != end);
+}
+
+static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ pmd_t *pmdp, *p;
+ unsigned long next;
+
+ if (pud_none(*pud)) {
+ p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
+ set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ }
+
+ pmdp = pmd_offset(pud, 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));
+ memset(__va(phys_addr), KASAN_SHADOW_INIT, PMD_SIZE);
+ continue;
+ }
+ }
+
+ kasan_populate_pte(pmdp, vaddr, next);
+ } while (pmdp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_populate_pud(p4d_t *p4d,
+ unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ pud_t *pudp, *p;
+ unsigned long next;
+
+ if (p4d_none(*p4d)) {
+ p = memblock_alloc(PTRS_PER_PUD * sizeof(pud_t), PAGE_SIZE);
+ set_p4d(p4d, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ }
+
+ pudp = pud_offset(p4d, vaddr);
+
+ do {
+ next = pud_addr_end(vaddr, end);
+
+ if (pud_none(*pudp) && IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
+ phys_addr = memblock_phys_alloc(PUD_SIZE, PUD_SIZE);
+ if (phys_addr) {
+ set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ memset(__va(phys_addr), KASAN_SHADOW_INIT, PUD_SIZE);
+ continue;
+ }
+ }
+
+ kasan_populate_pmd(pudp, vaddr, next);
+ } while (pudp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_populate_p4d(pgd_t *pgd,
+ unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ p4d_t *p4dp, *p;
+ unsigned long next;
+
+ if (pgd_none(*pgd)) {
+ p = memblock_alloc(PTRS_PER_P4D * sizeof(p4d_t), PAGE_SIZE);
+ set_pgd(pgd, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ }
+
+ p4dp = p4d_offset(pgd, vaddr);
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+
+ if (p4d_none(*p4dp) && IS_ALIGNED(vaddr, P4D_SIZE) && (next - vaddr) >= P4D_SIZE) {
+ phys_addr = memblock_phys_alloc(P4D_SIZE, P4D_SIZE);
+ if (phys_addr) {
+ set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ memset(__va(phys_addr), KASAN_SHADOW_INIT, P4D_SIZE);
+ continue;
+ }
+ }
+
+ kasan_populate_pud(p4dp, vaddr, next);
+ } while (p4dp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_populate_pgd(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ phys_addr_t phys_addr;
+ unsigned long next;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+
+ if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
+ (next - vaddr) >= PGDIR_SIZE) {
+ phys_addr = memblock_phys_alloc(PGDIR_SIZE, PGDIR_SIZE);
+ if (phys_addr) {
+ set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_KERNEL));
+ memset(__va(phys_addr), KASAN_SHADOW_INIT, PGDIR_SIZE);
+ continue;
+ }
+ }
+
+ kasan_populate_p4d(pgdp, vaddr, next);
+ } while (pgdp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_clear_pud(p4d_t *p4dp,
+ unsigned long vaddr, unsigned long end)
+{
+ pud_t *pudp, *base_pud;
+ unsigned long next;
+
+ if (!pgtable_l4_enabled) {
+ pudp = (pud_t *)p4dp;
+ } else {
+ base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
+ pudp = base_pud + pud_index(vaddr);
+ }
+
+ do {
+ next = pud_addr_end(vaddr, end);
+
+ if (IS_ALIGNED(vaddr, PUD_SIZE) && (next - vaddr) >= PUD_SIZE) {
+ pud_clear(pudp);
+ continue;
+ }
+
+ BUG();
+ } while (pudp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_clear_p4d(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ p4d_t *p4dp, *base_p4d;
+ unsigned long next;
+
+ if (!pgtable_l5_enabled) {
+ p4dp = (p4d_t *)pgdp;
+ } else {
+ base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
+ p4dp = base_p4d + p4d_index(vaddr);
+ }
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+
+ if (pgtable_l4_enabled && IS_ALIGNED(vaddr, P4D_SIZE) &&
+ (next - vaddr) >= P4D_SIZE) {
+ p4d_clear(p4dp);
+ continue;
+ }
+
+ kasan_early_clear_pud(p4dp, vaddr, next);
+ } while (p4dp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_clear_pgd(pgd_t *pgdp,
+ unsigned long vaddr, unsigned long end)
+{
+ unsigned long next;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+
+ if (pgtable_l5_enabled && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
+ (next - vaddr) >= PGDIR_SIZE) {
+ pgd_clear(pgdp);
+ continue;
+ }
+
+ kasan_early_clear_p4d(pgdp, vaddr, next);
+ } while (pgdp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_populate_pud(p4d_t *p4dp,
+ unsigned long vaddr,
+ unsigned long end)
+{
+ pud_t *pudp, *base_pud;
+ phys_addr_t phys_addr;
+ unsigned long next;
+
+ if (!pgtable_l4_enabled) {
+ pudp = (pud_t *)p4dp;
+ } else {
+ base_pud = pt_ops.get_pud_virt(pfn_to_phys(_p4d_pfn(*p4dp)));
+ 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) {
+ phys_addr = __pa((uintptr_t)kasan_early_shadow_pmd);
+ set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ }
+
+ BUG();
+ } while (pudp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_populate_p4d(pgd_t *pgdp,
+ unsigned long vaddr,
+ unsigned long end)
+{
+ p4d_t *p4dp, *base_p4d;
+ phys_addr_t phys_addr;
+ unsigned long next;
+
+ /*
+ * 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.
+ * Note that this test is then completely equivalent to
+ * p4dp = p4d_offset(pgdp, vaddr)
+ */
+ if (!pgtable_l5_enabled) {
+ p4dp = (p4d_t *)pgdp;
+ } else {
+ base_p4d = pt_ops.get_p4d_virt(pfn_to_phys(_pgd_pfn(*pgdp)));
+ 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) {
+ phys_addr = __pa((uintptr_t)kasan_early_shadow_pud);
+ set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ }
+
+ kasan_early_populate_pud(p4dp, vaddr, next);
+ } while (p4dp++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_early_populate_pgd(pgd_t *pgdp,
+ unsigned long vaddr,
+ unsigned long end)
+{
+ phys_addr_t phys_addr;
+ unsigned long next;
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+
+ if (pgd_none(*pgdp) && IS_ALIGNED(vaddr, PGDIR_SIZE) &&
+ (next - vaddr) >= PGDIR_SIZE) {
+ phys_addr = __pa((uintptr_t)kasan_early_shadow_p4d);
+ set_pgd(pgdp, pfn_pgd(PFN_DOWN(phys_addr), PAGE_TABLE));
+ continue;
+ }
+
+ kasan_early_populate_p4d(pgdp, vaddr, next);
+ } 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_early_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START),
+ KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ local_flush_tlb_all();
+}
+
+void __init kasan_swapper_init(void)
+{
+ kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START),
+ KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ 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);
+}
+
+static void __init kasan_shallow_populate_pud(p4d_t *p4d,
+ unsigned long vaddr, unsigned long end)
+{
+ unsigned long next;
+ void *p;
+ pud_t *pud_k = pud_offset(p4d, vaddr);
+
+ do {
+ next = pud_addr_end(vaddr, end);
+
+ if (pud_none(*pud_k)) {
+ p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_pud(pud_k, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ continue;
+ }
+
+ BUG();
+ } while (pud_k++, vaddr = next, vaddr != end);
+}
+
+static void __init kasan_shallow_populate_p4d(pgd_t *pgd,
+ unsigned long vaddr, unsigned long end)
+{
+ unsigned long next;
+ void *p;
+ p4d_t *p4d_k = p4d_offset(pgd, vaddr);
+
+ do {
+ next = p4d_addr_end(vaddr, end);
+
+ if (p4d_none(*p4d_k)) {
+ p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_p4d(p4d_k, pfn_p4d(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ continue;
+ }
+
+ kasan_shallow_populate_pud(p4d_k, vaddr, end);
+ } while (p4d_k++, vaddr = next, vaddr != end);
+}
+
+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);
+
+ do {
+ next = pgd_addr_end(vaddr, end);
+
+ if (pgd_none(*pgd_k)) {
+ p = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
+ set_pgd(pgd_k, pfn_pgd(PFN_DOWN(__pa(p)), PAGE_TABLE));
+ continue;
+ }
+
+ kasan_shallow_populate_p4d(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);
+}
+
+static void __init create_tmp_mapping(void)
+{
+ void *ptr;
+ p4d_t *base_p4d;
+
+ /*
+ * We need to clean the early mapping: this is hard to achieve "in-place",
+ * so install a temporary mapping like arm64 and x86 do.
+ */
+ memcpy(tmp_pg_dir, swapper_pg_dir, sizeof(pgd_t) * PTRS_PER_PGD);
+
+ /* Copy the last p4d since it is shared with the kernel mapping. */
+ if (pgtable_l5_enabled) {
+ ptr = (p4d_t *)pgd_page_vaddr(*pgd_offset_k(KASAN_SHADOW_END));
+ memcpy(tmp_p4d, ptr, sizeof(p4d_t) * PTRS_PER_P4D);
+ set_pgd(&tmp_pg_dir[pgd_index(KASAN_SHADOW_END)],
+ pfn_pgd(PFN_DOWN(__pa(tmp_p4d)), PAGE_TABLE));
+ base_p4d = tmp_p4d;
+ } else {
+ base_p4d = (p4d_t *)tmp_pg_dir;
+ }
+
+ /* Copy the last pud since it is shared with the kernel mapping. */
+ if (pgtable_l4_enabled) {
+ ptr = (pud_t *)p4d_page_vaddr(*(base_p4d + p4d_index(KASAN_SHADOW_END)));
+ memcpy(tmp_pud, ptr, sizeof(pud_t) * PTRS_PER_PUD);
+ set_p4d(&base_p4d[p4d_index(KASAN_SHADOW_END)],
+ pfn_p4d(PFN_DOWN(__pa(tmp_pud)), PAGE_TABLE));
+ }
+}
+
+void __init kasan_init(void)
+{
+ phys_addr_t p_start, p_end;
+ u64 i;
+
+ create_tmp_mapping();
+ csr_write(CSR_SATP, PFN_DOWN(__pa(tmp_pg_dir)) | satp_mode);
+
+ kasan_early_clear_pgd(pgd_offset_k(KASAN_SHADOW_START),
+ KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ kasan_populate_early_shadow((void *)kasan_mem_to_shadow((void *)FIXADDR_START),
+ (void *)kasan_mem_to_shadow((void *)VMALLOC_START));
+
+ 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));
+ /* Shallow populate modules and BPF which are vmalloc-allocated */
+ kasan_shallow_populate(
+ (void *)kasan_mem_to_shadow((void *)MODULES_VADDR),
+ (void *)kasan_mem_to_shadow((void *)MODULES_END));
+ } else {
+ kasan_populate_early_shadow((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 */
+ kasan_populate(kasan_mem_to_shadow((const void *)MODULES_END),
+ 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;
+
+ csr_write(CSR_SATP, PFN_DOWN(__pa(swapper_pg_dir)) | satp_mode);
+ local_flush_tlb_all();
+}