108 lines
2.6 KiB
C
108 lines
2.6 KiB
C
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#include <linux/bootmem.h>
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#include <linux/kasan.h>
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#include <linux/kdebug.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <linux/vmalloc.h>
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#include <asm/tlbflush.h>
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#include <asm/sections.h>
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extern pgd_t early_level4_pgt[PTRS_PER_PGD];
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extern struct range pfn_mapped[E820_X_MAX];
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static int __init map_range(struct range *range)
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{
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unsigned long start;
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unsigned long end;
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start = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->start));
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end = (unsigned long)kasan_mem_to_shadow(pfn_to_kaddr(range->end));
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/*
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* end + 1 here is intentional. We check several shadow bytes in advance
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* to slightly speed up fastpath. In some rare cases we could cross
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* boundary of mapped shadow, so we just map some more here.
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*/
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return vmemmap_populate(start, end + 1, NUMA_NO_NODE);
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}
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static void __init clear_pgds(unsigned long start,
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unsigned long end)
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{
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for (; start < end; start += PGDIR_SIZE)
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pgd_clear(pgd_offset_k(start));
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}
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void __init kasan_map_early_shadow(pgd_t *pgd)
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{
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int i;
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unsigned long start = KASAN_SHADOW_START;
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unsigned long end = KASAN_SHADOW_END;
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for (i = pgd_index(start); start < end; i++) {
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pgd[i] = __pgd(__pa_nodebug(kasan_zero_pud)
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| _KERNPG_TABLE);
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start += PGDIR_SIZE;
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}
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}
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#ifdef CONFIG_KASAN_INLINE
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static int kasan_die_handler(struct notifier_block *self,
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unsigned long val,
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void *data)
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{
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if (val == DIE_GPF) {
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pr_emerg("CONFIG_KASAN_INLINE enabled");
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pr_emerg("GPF could be caused by NULL-ptr deref or user memory access");
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}
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return NOTIFY_OK;
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}
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static struct notifier_block kasan_die_notifier = {
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.notifier_call = kasan_die_handler,
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};
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#endif
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void __init kasan_init(void)
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{
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int i;
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#ifdef CONFIG_KASAN_INLINE
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register_die_notifier(&kasan_die_notifier);
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#endif
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memcpy(early_level4_pgt, init_level4_pgt, sizeof(early_level4_pgt));
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load_cr3(early_level4_pgt);
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clear_pgds(KASAN_SHADOW_START, KASAN_SHADOW_END);
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kasan_populate_zero_shadow((void *)KASAN_SHADOW_START,
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kasan_mem_to_shadow((void *)PAGE_OFFSET));
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for (i = 0; i < E820_X_MAX; i++) {
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if (pfn_mapped[i].end == 0)
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break;
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if (map_range(&pfn_mapped[i]))
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panic("kasan: unable to allocate shadow!");
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}
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kasan_populate_zero_shadow(
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kasan_mem_to_shadow((void *)PAGE_OFFSET + MAXMEM),
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kasan_mem_to_shadow((void *)__START_KERNEL_map));
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vmemmap_populate((unsigned long)kasan_mem_to_shadow(_stext),
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(unsigned long)kasan_mem_to_shadow(_end),
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NUMA_NO_NODE);
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kasan_populate_zero_shadow(kasan_mem_to_shadow((void *)MODULES_END),
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(void *)KASAN_SHADOW_END);
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memset(kasan_zero_page, 0, PAGE_SIZE);
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load_cr3(init_level4_pgt);
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init_task.kasan_depth = 0;
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pr_info("KernelAddressSanitizer initialized\n");
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}
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