--- /dev/null
+#include <linux/bootmem.h>
+#include <linux/kasan.h>
+#include <linux/kdebug.h>
+#include <linux/mm.h>
+#include <linux/sched.h>
+#include <linux/vmalloc.h>
+
+#include <asm/tlbflush.h>
+#include <asm/sections.h>
+
+extern pgd_t early_level4_pgt[PTRS_PER_PGD];
+extern struct range pfn_mapped[E820_X_MAX];
+
+extern unsigned char kasan_zero_page[PAGE_SIZE];
+
+static int __init map_range(struct range *range)
+{
+ unsigned long start;
+ unsigned long end;
+
+ start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
+ end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
+
+ /*
+ * end + 1 here is intentional. We check several shadow bytes in advance
+ * to slightly speed up fastpath. In some rare cases we could cross
+ * boundary of mapped shadow, so we just map some more here.
+ */
+ return vmemmap_populate(start, end + 1, NUMA_NO_NODE);
+}
+
+static void __init clear_pgds(unsigned long start,
+ unsigned long end)
+{
+ for (; start < end; start += PGDIR_SIZE)
+ pgd_clear(pgd_offset_k(start));
+}
+
+void __init kasan_map_early_shadow(pgd_t *pgd)
+{
+ int i;
+ unsigned long start = KASAN_SHADOW_START;
+ unsigned long end = KASAN_SHADOW_END;
+
+ for (i = pgd_index(start); start < end; i++) {
+ pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud)
+ | _KERNPG_TABLE);
+ start += PGDIR_SIZE;
+ }
+}
+
+static int __init zero_pte_populate(pmd_t *pmd, unsigned long addr,
+ unsigned long end)
+{
+ pte_t *pte = pte_offset_kernel(pmd, addr);
+
+ while (addr + PAGE_SIZE <= end) {
+ WARN_ON(!pte_none(*pte));
+ set_pte(pte, __pte(__pa_nodebug(kasan_zero_page)
+ | __PAGE_KERNEL_RO));
+ addr += PAGE_SIZE;
+ pte = pte_offset_kernel(pmd, addr);
+ }
+ return 0;
+}
+
+static int __init zero_pmd_populate(pud_t *pud, unsigned long addr,
+ unsigned long end)
+{
+ int ret = 0;
+ pmd_t *pmd = pmd_offset(pud, addr);
+
+ while (IS_ALIGNED(addr, PMD_SIZE) && addr + PMD_SIZE <= end) {
+ WARN_ON(!pmd_none(*pmd));
+ set_pmd(pmd, __pmd(__pa_nodebug(kasan_zero_pte)
+ | __PAGE_KERNEL_RO));
+ addr += PMD_SIZE;
+ pmd = pmd_offset(pud, addr);
+ }
+ if (addr < end) {
+ if (pmd_none(*pmd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+ if (!p)
+ return -ENOMEM;
+ set_pmd(pmd, __pmd(__pa_nodebug(p) | _KERNPG_TABLE));
+ }
+ ret = zero_pte_populate(pmd, addr, end);
+ }
+ return ret;
+}
+
+
+static int __init zero_pud_populate(pgd_t *pgd, unsigned long addr,
+ unsigned long end)
+{
+ int ret = 0;
+ pud_t *pud = pud_offset(pgd, addr);
+
+ while (IS_ALIGNED(addr, PUD_SIZE) && addr + PUD_SIZE <= end) {
+ WARN_ON(!pud_none(*pud));
+ set_pud(pud, __pud(__pa_nodebug(kasan_zero_pmd)
+ | __PAGE_KERNEL_RO));
+ addr += PUD_SIZE;
+ pud = pud_offset(pgd, addr);
+ }
+
+ if (addr < end) {
+ if (pud_none(*pud)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+ if (!p)
+ return -ENOMEM;
+ set_pud(pud, __pud(__pa_nodebug(p) | _KERNPG_TABLE));
+ }
+ ret = zero_pmd_populate(pud, addr, end);
+ }
+ return ret;
+}
+
+static int __init zero_pgd_populate(unsigned long addr, unsigned long end)
+{
+ int ret = 0;
+ pgd_t *pgd = pgd_offset_k(addr);
+
+ while (IS_ALIGNED(addr, PGDIR_SIZE) && addr + PGDIR_SIZE <= end) {
+ WARN_ON(!pgd_none(*pgd));
+ set_pgd(pgd, __pgd(__pa_nodebug(kasan_zero_pud)
+ | __PAGE_KERNEL_RO));
+ addr += PGDIR_SIZE;
+ pgd = pgd_offset_k(addr);
+ }
+
+ if (addr < end) {
+ if (pgd_none(*pgd)) {
+ void *p = vmemmap_alloc_block(PAGE_SIZE, NUMA_NO_NODE);
+ if (!p)
+ return -ENOMEM;
+ set_pgd(pgd, __pgd(__pa_nodebug(p) | _KERNPG_TABLE));
+ }
+ ret = zero_pud_populate(pgd, addr, end);
+ }
+ return ret;
+}
+
+
+static void __init populate_zero_shadow(const void *start, const void *end)
+{
+ if (zero_pgd_populate((unsigned long)start, (unsigned long)end))
+ panic("kasan: unable to map zero shadow!");
+}
+
+
+#ifdef CONFIG_KASAN_INLINE
+static int kasan_die_handler(struct notifier_block *self,
+ unsigned long val,
+ void *data)
+{
+ if (val == DIE_GPF) {
+ pr_emerg("CONFIG_KASAN_INLINE enabled");
+ pr_emerg("GPF could be caused by NULL-ptr deref or user memory access");
+ }
+ return NOTIFY_OK;
+}
+
+static struct notifier_block kasan_die_notifier = {
+ .notifier_call = kasan_die_handler,
+};
+#endif
+
+void __init kasan_init(void)
+{
+ int i;
+
+#ifdef CONFIG_KASAN_INLINE
+ register_die_notifier(&kasan_die_notifier);
+#endif
+
+ memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
+ load_cr3(early_level4_pgt);
+
+ clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
+
+ populate_zero_shadow((void *)KASAN_SHADOW_START,
+ kasan_mem_to_shadow((void *)PAGE_OFFSET));
+
+ for (i = 0; i < E820_X_MAX; i++) {
+ if (pfn_mapped[i].end == 0)
+ break;
+
+ if (map_range(&pfn_mapped[i]))
+ panic("kasan: unable to allocate shadow!");
+ }
+
+ populate_zero_shadow(kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
+ (void *)KASAN_SHADOW_END);
+
+ memset(kasan_zero_page, 0, PAGE_SIZE);
+
+ load_cr3(init_level4_pgt);
+}
projects / users / hch / configfs.git / commitdiff