Merge patch series "RISC-V kasan rework"
authorPalmer Dabbelt <palmer@rivosinc.com>
Wed, 19 Apr 2023 14:24:56 +0000 (07:24 -0700)
committerPalmer Dabbelt <palmer@rivosinc.com>
Wed, 19 Apr 2023 14:24:56 +0000 (07:24 -0700)
Alexandre Ghiti <alexghiti@rivosinc.com> says:

As described in patch 2, our current kasan implementation is intricate,
so I tried to simplify the implementation and mimic what arm64/x86 are
doing.

In addition it fixes UEFI bootflow with a kasan kernel and kasan inline
instrumentation: all kasan configurations were tested on a large ubuntu
kernel with success with KASAN_KUNIT_TEST and KASAN_MODULE_TEST.

inline ubuntu config + uefi:
 sv39: OK
 sv48: OK
 sv57: OK

outline ubuntu config + uefi:
 sv39: OK
 sv48: OK
 sv57: OK

Actually 1 test always fails with KASAN_KUNIT_TEST that I have to check:
KASAN failure expected in "set_bit(nr, addr)", but none occurrred

Note that Palmer recently proposed to remove COMMAND_LINE_SIZE from the
userspace abi
https://lore.kernel.org/lkml/20221211061358.28035-1-palmer@rivosinc.com/T/
so that we can finally increase the command line to fit all kasan kernel
parameters.

All of this should hopefully fix the syzkaller riscv build that has been
failing for a few months now, any test is appreciated and if I can help
in any way, please ask.

* b4-shazam-merge:
  riscv: Unconditionnally select KASAN_VMALLOC if KASAN
  riscv: Fix ptdump when KASAN is enabled
  riscv: Fix EFI stub usage of KASAN instrumented strcmp function
  riscv: Move DTB_EARLY_BASE_VA to the kernel address space
  riscv: Rework kasan population functions
  riscv: Split early and final KASAN population functions

Link: https://lore.kernel.org/r/20230203075232.274282-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
arch/riscv/Kconfig
arch/riscv/kernel/image-vars.h
arch/riscv/mm/init.c
arch/riscv/mm/kasan_init.c
arch/riscv/mm/ptdump.c

index ba94d08..716e948 100644 (file)
@@ -120,6 +120,7 @@ config RISCV
        select HAVE_SYSCALL_TRACEPOINTS
        select IRQ_DOMAIN
        select IRQ_FORCED_THREADING
+       select KASAN_VMALLOC if KASAN
        select MODULES_USE_ELF_RELA if MODULES
        select MODULE_SECTIONS if MODULES
        select OF
index 7e2962e..1561615 100644 (file)
@@ -23,8 +23,6 @@
  * linked at. The routines below are all implemented in assembler in a
  * position independent manner
  */
-__efistub_strcmp               = strcmp;
-
 __efistub__start               = _start;
 __efistub__start_kernel                = _start_kernel;
 __efistub__end                 = _end;
index 7bd6679..f803671 100644 (file)
@@ -57,7 +57,7 @@ unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]
 EXPORT_SYMBOL(empty_zero_page);
 
 extern char _start[];
-#define DTB_EARLY_BASE_VA      PGDIR_SIZE
+#define DTB_EARLY_BASE_VA      (ADDRESS_SPACE_END - (PTRS_PER_PGD / 2 * PGDIR_SIZE) + 1)
 void *_dtb_early_va __initdata;
 uintptr_t _dtb_early_pa __initdata;
 
index e122670..8fc0efc 100644 (file)
  * 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.
+ * 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.
  */
 
 extern pgd_t early_pg_dir[PTRS_PER_PGD];
+pgd_t tmp_pg_dir[PTRS_PER_PGD] __page_aligned_bss;
+p4d_t tmp_p4d[PTRS_PER_P4D] __page_aligned_bss;
+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, *base_pte;
+       pte_t *ptep, *p;
 
-       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);
+       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 = base_pte + pte_index(vaddr);
+       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);
-
-       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;
+       pmd_t *pmdp, *p;
        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);
+               p = memblock_alloc(PTRS_PER_PMD * sizeof(pmd_t), PAGE_SIZE);
+               set_pud(pud, pfn_pud(PFN_DOWN(__pa(p)), PAGE_TABLE));
        }
 
-       pmdp = base_pmd + pmd_index(vaddr);
+       pmdp = pmd_offset(pud, vaddr);
 
        do {
                next = pmd_addr_end(vaddr, end);
@@ -78,157 +68,77 @@ static void __init kasan_populate_pmd(pud_t *pud, unsigned long vaddr, unsigned
                        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);
-
-       /*
-        * 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)
+static void __init kasan_populate_pud(p4d_t *p4d,
+                                     unsigned long vaddr, unsigned long end)
 {
        phys_addr_t phys_addr;
-       pud_t *pudp, *base_pud;
+       pud_t *pudp, *p;
        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);
-               }
+       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 = base_pud + pud_index(vaddr);
+       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) {
-                       if (early) {
-                               phys_addr = __pa(((uintptr_t)kasan_early_shadow_pmd));
-                               set_pud(pudp, pfn_pud(PFN_DOWN(phys_addr), PAGE_TABLE));
+                       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;
-                       } 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)
+                                     unsigned long vaddr, unsigned long end)
 {
        phys_addr_t phys_addr;
-       p4d_t *p4dp, *base_p4d;
+       p4d_t *p4dp, *p;
        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);
-               }
+       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 = base_p4d + p4d_index(vaddr);
+       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) {
-                       if (early) {
-                               phys_addr = __pa(((uintptr_t)kasan_early_shadow_pud));
-                               set_p4d(p4dp, pfn_p4d(PFN_DOWN(phys_addr), PAGE_TABLE));
+                       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;
-                       } 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);
+               kasan_populate_pud(p4dp, vaddr, next);
        } 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)
+                                     unsigned long vaddr, unsigned long end)
 {
        phys_addr_t phys_addr;
        unsigned long next;
@@ -236,29 +146,174 @@ static void __init kasan_populate_pgd(pgd_t *pgdp,
        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));
+               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;
-                       } 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);
+               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);
 }
 
@@ -295,16 +350,16 @@ asmlinkage void __init kasan_early_init(void)
                                        PAGE_TABLE));
        }
 
-       kasan_populate_pgd(early_pg_dir + pgd_index(KASAN_SHADOW_START),
-                          KASAN_SHADOW_START, KASAN_SHADOW_END, true);
+       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_populate_pgd(pgd_offset_k(KASAN_SHADOW_START),
-                          KASAN_SHADOW_START, KASAN_SHADOW_END, true);
+       kasan_early_populate_pgd(pgd_offset_k(KASAN_SHADOW_START),
+                                KASAN_SHADOW_START, KASAN_SHADOW_END);
 
        local_flush_tlb_all();
 }
@@ -314,118 +369,65 @@ 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);
+       kasan_populate_pgd(pgd_offset_k(vaddr), vaddr, vend);
 }
 
-static void __init kasan_shallow_populate_pmd(pgd_t *pgdp,
+static void __init kasan_shallow_populate_pud(p4d_t *p4d,
                                              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);
+       void *p;
+       pud_t *pud_k = pud_offset(p4d, 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)
+               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;
+               }
 
-               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);
+               BUG();
+       } while (pud_k++, vaddr = next, vaddr != end);
 }
 
-static void __init kasan_shallow_populate_p4d(pgd_t *pgdp,
+static void __init kasan_shallow_populate_p4d(pgd_t *pgd,
                                              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);
+       void *p;
+       p4d_t *p4d_k = p4d_offset(pgd, 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)
+               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;
+               }
 
-               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);
+               kasan_shallow_populate_pud(p4d_k, vaddr, end);
+       } while (p4d_k++, 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) {
+               if (pgd_none(*pgd_k)) {
                        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);
+               kasan_shallow_populate_p4d(pgd_k, vaddr, next);
        } while (pgd_k++, vaddr = next, vaddr != end);
 }
 
@@ -435,7 +437,37 @@ static void __init kasan_shallow_populate(void *start, void *end)
        unsigned long vend = PAGE_ALIGN((unsigned long)end);
 
        kasan_shallow_populate_pgd(vaddr, vend);
-       local_flush_tlb_all();
+}
+
+static void 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)
@@ -443,10 +475,27 @@ void __init kasan_init(void)
        phys_addr_t p_start, p_end;
        u64 i;
 
-       if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
+       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) {
@@ -459,8 +508,8 @@ void __init kasan_init(void)
                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),
+       /* 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++)
@@ -471,4 +520,7 @@ void __init kasan_init(void)
 
        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();
 }
index 830e7de..20a9f99 100644 (file)
@@ -59,10 +59,6 @@ struct ptd_mm_info {
 };
 
 enum address_markers_idx {
-#ifdef CONFIG_KASAN
-       KASAN_SHADOW_START_NR,
-       KASAN_SHADOW_END_NR,
-#endif
        FIXMAP_START_NR,
        FIXMAP_END_NR,
        PCI_IO_START_NR,
@@ -74,6 +70,10 @@ enum address_markers_idx {
        VMALLOC_START_NR,
        VMALLOC_END_NR,
        PAGE_OFFSET_NR,
+#ifdef CONFIG_KASAN
+       KASAN_SHADOW_START_NR,
+       KASAN_SHADOW_END_NR,
+#endif
 #ifdef CONFIG_64BIT
        MODULES_MAPPING_NR,
        KERNEL_MAPPING_NR,
@@ -82,10 +82,6 @@ enum address_markers_idx {
 };
 
 static struct addr_marker address_markers[] = {
-#ifdef CONFIG_KASAN
-       {0, "Kasan shadow start"},
-       {0, "Kasan shadow end"},
-#endif
        {0, "Fixmap start"},
        {0, "Fixmap end"},
        {0, "PCI I/O start"},
@@ -97,6 +93,10 @@ static struct addr_marker address_markers[] = {
        {0, "vmalloc() area"},
        {0, "vmalloc() end"},
        {0, "Linear mapping"},
+#ifdef CONFIG_KASAN
+       {0, "Kasan shadow start"},
+       {0, "Kasan shadow end"},
+#endif
 #ifdef CONFIG_64BIT
        {0, "Modules/BPF mapping"},
        {0, "Kernel mapping"},
@@ -362,10 +362,6 @@ static int __init ptdump_init(void)
 {
        unsigned int i, j;
 
-#ifdef CONFIG_KASAN
-       address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START;
-       address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END;
-#endif
        address_markers[FIXMAP_START_NR].start_address = FIXADDR_START;
        address_markers[FIXMAP_END_NR].start_address = FIXADDR_TOP;
        address_markers[PCI_IO_START_NR].start_address = PCI_IO_START;
@@ -377,6 +373,10 @@ static int __init ptdump_init(void)
        address_markers[VMALLOC_START_NR].start_address = VMALLOC_START;
        address_markers[VMALLOC_END_NR].start_address = VMALLOC_END;
        address_markers[PAGE_OFFSET_NR].start_address = PAGE_OFFSET;
+#ifdef CONFIG_KASAN
+       address_markers[KASAN_SHADOW_START_NR].start_address = KASAN_SHADOW_START;
+       address_markers[KASAN_SHADOW_END_NR].start_address = KASAN_SHADOW_END;
+#endif
 #ifdef CONFIG_64BIT
        address_markers[MODULES_MAPPING_NR].start_address = MODULES_VADDR;
        address_markers[KERNEL_MAPPING_NR].start_address = kernel_map.virt_addr;