summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm/kasan/init_32.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/powerpc/mm/kasan/init_32.c')
-rw-r--r--arch/powerpc/mm/kasan/init_32.c191
1 files changed, 191 insertions, 0 deletions
diff --git a/arch/powerpc/mm/kasan/init_32.c b/arch/powerpc/mm/kasan/init_32.c
new file mode 100644
index 000000000..a70828a6d
--- /dev/null
+++ b/arch/powerpc/mm/kasan/init_32.c
@@ -0,0 +1,191 @@
+// SPDX-License-Identifier: GPL-2.0
+
+#define DISABLE_BRANCH_PROFILING
+
+#include <linux/kasan.h>
+#include <linux/printk.h>
+#include <linux/memblock.h>
+#include <linux/sched/task.h>
+#include <asm/pgalloc.h>
+#include <asm/code-patching.h>
+#include <mm/mmu_decl.h>
+
+static pgprot_t __init kasan_prot_ro(void)
+{
+ if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
+ return PAGE_READONLY;
+
+ return PAGE_KERNEL_RO;
+}
+
+static void __init kasan_populate_pte(pte_t *ptep, pgprot_t prot)
+{
+ unsigned long va = (unsigned long)kasan_early_shadow_page;
+ phys_addr_t pa = __pa(kasan_early_shadow_page);
+ int i;
+
+ for (i = 0; i < PTRS_PER_PTE; i++, ptep++)
+ __set_pte_at(&init_mm, va, ptep, pfn_pte(PHYS_PFN(pa), prot), 1);
+}
+
+int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
+{
+ pmd_t *pmd;
+ unsigned long k_cur, k_next;
+
+ pmd = pmd_off_k(k_start);
+
+ for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
+ pte_t *new;
+
+ k_next = pgd_addr_end(k_cur, k_end);
+ if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
+ continue;
+
+ new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
+
+ if (!new)
+ return -ENOMEM;
+ kasan_populate_pte(new, PAGE_KERNEL);
+ pmd_populate_kernel(&init_mm, pmd, new);
+ }
+ return 0;
+}
+
+int __init __weak kasan_init_region(void *start, size_t size)
+{
+ unsigned long k_start = (unsigned long)kasan_mem_to_shadow(start);
+ unsigned long k_end = (unsigned long)kasan_mem_to_shadow(start + size);
+ unsigned long k_cur;
+ int ret;
+ void *block;
+
+ ret = kasan_init_shadow_page_tables(k_start, k_end);
+ if (ret)
+ return ret;
+
+ block = memblock_alloc(k_end - k_start, PAGE_SIZE);
+ if (!block)
+ return -ENOMEM;
+
+ for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
+ pmd_t *pmd = pmd_off_k(k_cur);
+ void *va = block + k_cur - k_start;
+ pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
+
+ __set_pte_at(&init_mm, k_cur, pte_offset_kernel(pmd, k_cur), pte, 0);
+ }
+ flush_tlb_kernel_range(k_start, k_end);
+ return 0;
+}
+
+void __init
+kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
+{
+ unsigned long k_cur;
+
+ for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) {
+ pmd_t *pmd = pmd_off_k(k_cur);
+ pte_t *ptep = pte_offset_kernel(pmd, k_cur);
+
+ if (pte_page(*ptep) != virt_to_page(lm_alias(kasan_early_shadow_page)))
+ continue;
+
+ __set_pte_at(&init_mm, k_cur, ptep, pte, 0);
+ }
+
+ flush_tlb_kernel_range(k_start, k_end);
+}
+
+static void __init kasan_remap_early_shadow_ro(void)
+{
+ pgprot_t prot = kasan_prot_ro();
+ phys_addr_t pa = __pa(kasan_early_shadow_page);
+
+ kasan_populate_pte(kasan_early_shadow_pte, prot);
+
+ kasan_update_early_region(KASAN_SHADOW_START, KASAN_SHADOW_END,
+ pfn_pte(PHYS_PFN(pa), prot));
+}
+
+static void __init kasan_unmap_early_shadow_vmalloc(void)
+{
+ unsigned long k_start = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_START);
+ unsigned long k_end = (unsigned long)kasan_mem_to_shadow((void *)VMALLOC_END);
+
+ kasan_update_early_region(k_start, k_end, __pte(0));
+
+#ifdef MODULES_VADDR
+ k_start = (unsigned long)kasan_mem_to_shadow((void *)MODULES_VADDR);
+ k_end = (unsigned long)kasan_mem_to_shadow((void *)MODULES_END);
+ kasan_update_early_region(k_start, k_end, __pte(0));
+#endif
+}
+
+void __init kasan_mmu_init(void)
+{
+ int ret;
+
+ if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE)) {
+ ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ if (ret)
+ panic("kasan: kasan_init_shadow_page_tables() failed");
+ }
+}
+
+void __init kasan_init(void)
+{
+ phys_addr_t base, end;
+ u64 i;
+ int ret;
+
+ for_each_mem_range(i, &base, &end) {
+ phys_addr_t top = min(end, total_lowmem);
+
+ if (base >= top)
+ continue;
+
+ ret = kasan_init_region(__va(base), top - base);
+ if (ret)
+ panic("kasan: kasan_init_region() failed");
+ }
+
+ if (IS_ENABLED(CONFIG_KASAN_VMALLOC)) {
+ ret = kasan_init_shadow_page_tables(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ if (ret)
+ panic("kasan: kasan_init_shadow_page_tables() failed");
+ }
+
+ kasan_remap_early_shadow_ro();
+
+ clear_page(kasan_early_shadow_page);
+
+ /* At this point kasan is fully initialized. Enable error messages */
+ init_task.kasan_depth = 0;
+ pr_info("KASAN init done\n");
+}
+
+void __init kasan_late_init(void)
+{
+ if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
+ kasan_unmap_early_shadow_vmalloc();
+}
+
+void __init kasan_early_init(void)
+{
+ unsigned long addr = KASAN_SHADOW_START;
+ unsigned long end = KASAN_SHADOW_END;
+ unsigned long next;
+ pmd_t *pmd = pmd_off_k(addr);
+
+ BUILD_BUG_ON(KASAN_SHADOW_START & ~PGDIR_MASK);
+
+ kasan_populate_pte(kasan_early_shadow_pte, PAGE_KERNEL);
+
+ do {
+ next = pgd_addr_end(addr, end);
+ pmd_populate_kernel(&init_mm, pmd, kasan_early_shadow_pte);
+ } while (pmd++, addr = next, addr != end);
+}