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// SPDX-License-Identifier: GPL-2.0
#define DISABLE_BRANCH_PROFILING
#include <linux/kasan.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/moduleloader.h>
#include <linux/sched/task.h>
#include <linux/vmalloc.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), 0);
}
static int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
{
pmd_t *pmd;
unsigned long k_cur, k_next;
pte_t *new = NULL;
pmd = pmd_offset(pud_offset(pgd_offset_k(k_start), k_start), k_start);
for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
k_next = pgd_addr_end(k_cur, k_end);
if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
continue;
if (!new)
new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);
if (!new)
return -ENOMEM;
kasan_populate_pte(new, PAGE_KERNEL);
smp_wmb(); /* See comment in __pte_alloc */
spin_lock(&init_mm.page_table_lock);
/* Has another populated it ? */
if (likely((void *)pmd_page_vaddr(*pmd) == kasan_early_shadow_pte)) {
pmd_populate_kernel(&init_mm, pmd, new);
new = NULL;
}
spin_unlock(&init_mm.page_table_lock);
}
return 0;
}
static int __init 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);
for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
void *va = block + k_cur - k_start;
pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);
if (!va)
return -ENOMEM;
__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;
}
static void __init kasan_remap_early_shadow_ro(void)
{
pgprot_t prot = kasan_prot_ro();
unsigned long k_start = KASAN_SHADOW_START;
unsigned long k_end = KASAN_SHADOW_END;
unsigned long k_cur;
phys_addr_t pa = __pa(kasan_early_shadow_page);
kasan_populate_pte(kasan_early_shadow_pte, prot);
for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
pte_t *ptep = pte_offset_kernel(pmd, k_cur);
if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
continue;
__set_pte_at(&init_mm, k_cur, ptep, pfn_pte(PHYS_PFN(pa), prot), 0);
}
flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
}
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);
unsigned long k_cur;
phys_addr_t pa = __pa(kasan_early_shadow_page);
for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
pmd_t *pmd = pmd_offset(pud_offset(pgd_offset_k(k_cur), k_cur), k_cur);
pte_t *ptep = pte_offset_kernel(pmd, k_cur);
if ((pte_val(*ptep) & PTE_RPN_MASK) != pa)
continue;
__set_pte_at(&init_mm, k_cur, ptep, __pte(0), 0);
}
flush_tlb_kernel_range(k_start, k_end);
}
void __init kasan_mmu_init(void)
{
int ret;
struct memblock_region *reg;
if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE) ||
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");
}
for_each_memblock(memory, reg) {
phys_addr_t base = reg->base;
phys_addr_t top = min(base + reg->size, total_lowmem);
if (base >= top)
continue;
ret = kasan_init_region(__va(base), top - base);
if (ret)
panic("kasan: kasan_init_region() failed");
}
}
void __init kasan_init(void)
{
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();
}
#ifdef CONFIG_PPC_BOOK3S_32
u8 __initdata early_hash[256 << 10] __aligned(256 << 10) = {0};
static void __init kasan_early_hash_table(void)
{
unsigned int hash = __pa(early_hash);
modify_instruction_site(&patch__hash_page_A0, 0xffff, hash >> 16);
modify_instruction_site(&patch__flush_hash_A0, 0xffff, hash >> 16);
Hash = (struct hash_pte *)early_hash;
}
#else
static void __init kasan_early_hash_table(void) {}
#endif
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_offset(pud_offset(pgd_offset_k(addr), addr), 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);
if (early_mmu_has_feature(MMU_FTR_HPTE_TABLE))
kasan_early_hash_table();
}
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