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// SPDX-License-Identifier: GPL-2.0
/*
* KASAN for 64-bit Book3e powerpc
*
* Copyright 2022, Christophe Leroy, CS GROUP France
*/
#define DISABLE_BRANCH_PROFILING
#include <linux/kasan.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/set_memory.h>
#include <asm/pgalloc.h>
static inline bool kasan_pud_table(p4d_t p4d)
{
return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
}
static inline bool kasan_pmd_table(pud_t pud)
{
return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
}
static inline bool kasan_pte_table(pmd_t pmd)
{
return pmd_page(pmd) == virt_to_page(lm_alias(kasan_early_shadow_pte));
}
static int __init kasan_map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
{
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp;
pmd_t *pmdp;
pte_t *ptep;
pgdp = pgd_offset_k(ea);
p4dp = p4d_offset(pgdp, ea);
if (kasan_pud_table(*p4dp)) {
pudp = memblock_alloc(PUD_TABLE_SIZE, PUD_TABLE_SIZE);
memcpy(pudp, kasan_early_shadow_pud, PUD_TABLE_SIZE);
p4d_populate(&init_mm, p4dp, pudp);
}
pudp = pud_offset(p4dp, ea);
if (kasan_pmd_table(*pudp)) {
pmdp = memblock_alloc(PMD_TABLE_SIZE, PMD_TABLE_SIZE);
memcpy(pmdp, kasan_early_shadow_pmd, PMD_TABLE_SIZE);
pud_populate(&init_mm, pudp, pmdp);
}
pmdp = pmd_offset(pudp, ea);
if (kasan_pte_table(*pmdp)) {
ptep = memblock_alloc(PTE_TABLE_SIZE, PTE_TABLE_SIZE);
memcpy(ptep, kasan_early_shadow_pte, PTE_TABLE_SIZE);
pmd_populate_kernel(&init_mm, pmdp, ptep);
}
ptep = pte_offset_kernel(pmdp, ea);
__set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot), 0);
return 0;
}
static void __init kasan_init_phys_region(void *start, void *end)
{
unsigned long k_start, k_end, k_cur;
void *va;
if (start >= end)
return;
k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE);
k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE);
va = memblock_alloc(k_end - k_start, PAGE_SIZE);
for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE, va += PAGE_SIZE)
kasan_map_kernel_page(k_cur, __pa(va), PAGE_KERNEL);
}
void __init kasan_early_init(void)
{
int i;
unsigned long addr;
pgd_t *pgd = pgd_offset_k(KASAN_SHADOW_START);
pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL);
BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE));
BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE));
for (i = 0; i < PTRS_PER_PTE; i++)
__set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
&kasan_early_shadow_pte[i], zero_pte, 0);
for (i = 0; i < PTRS_PER_PMD; i++)
pmd_populate_kernel(&init_mm, &kasan_early_shadow_pmd[i],
kasan_early_shadow_pte);
for (i = 0; i < PTRS_PER_PUD; i++)
pud_populate(&init_mm, &kasan_early_shadow_pud[i],
kasan_early_shadow_pmd);
for (addr = KASAN_SHADOW_START; addr != KASAN_SHADOW_END; addr += PGDIR_SIZE)
p4d_populate(&init_mm, p4d_offset(pgd++, addr), kasan_early_shadow_pud);
}
void __init kasan_init(void)
{
phys_addr_t start, end;
u64 i;
pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO);
for_each_mem_range(i, &start, &end)
kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end));
if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
kasan_remove_zero_shadow((void *)VMALLOC_START, VMALLOC_SIZE);
for (i = 0; i < PTRS_PER_PTE; i++)
__set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
&kasan_early_shadow_pte[i], zero_pte, 0);
flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
memset(kasan_early_shadow_page, 0, PAGE_SIZE);
/* Enable error messages */
init_task.kasan_depth = 0;
pr_info("KASAN init done\n");
}
void __init kasan_late_init(void) { }
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