295454eda9
The kasan_init_phys_region() function maps shadow pages necessary for the ranges of the linear map backed by physical pages. Currently kasan_init_phys_region() is being passed physical addresses, but kasan_mem_to_shadow() expects virtual addresses. It works right now because the lower bits (12:64) of the kasan_mem_to_shadow() calculation are the same for the real and virtual addresses, so the actual PTE value is the same in the end. But virtual addresses are the intended input, so fix it. Signed-off-by: Benjamin Gray <bgray@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://msgid.link/20240212045020.70364-1-bgray@linux.ibm.com
133 lines
3.7 KiB
C
133 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* KASAN for 64-bit Book3e powerpc
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*
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* Copyright 2022, Christophe Leroy, CS GROUP France
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*/
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#define DISABLE_BRANCH_PROFILING
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#include <linux/kasan.h>
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#include <linux/printk.h>
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#include <linux/memblock.h>
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#include <linux/set_memory.h>
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#include <asm/pgalloc.h>
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static inline bool kasan_pud_table(p4d_t p4d)
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{
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return p4d_page(p4d) == virt_to_page(lm_alias(kasan_early_shadow_pud));
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}
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static inline bool kasan_pmd_table(pud_t pud)
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{
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return pud_page(pud) == virt_to_page(lm_alias(kasan_early_shadow_pmd));
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}
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static inline bool kasan_pte_table(pmd_t pmd)
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{
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return pmd_page(pmd) == virt_to_page(lm_alias(kasan_early_shadow_pte));
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}
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static int __init kasan_map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t prot)
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{
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pgd_t *pgdp;
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p4d_t *p4dp;
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pud_t *pudp;
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pmd_t *pmdp;
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pte_t *ptep;
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pgdp = pgd_offset_k(ea);
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p4dp = p4d_offset(pgdp, ea);
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if (kasan_pud_table(*p4dp)) {
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pudp = memblock_alloc(PUD_TABLE_SIZE, PUD_TABLE_SIZE);
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memcpy(pudp, kasan_early_shadow_pud, PUD_TABLE_SIZE);
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p4d_populate(&init_mm, p4dp, pudp);
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}
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pudp = pud_offset(p4dp, ea);
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if (kasan_pmd_table(*pudp)) {
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pmdp = memblock_alloc(PMD_TABLE_SIZE, PMD_TABLE_SIZE);
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memcpy(pmdp, kasan_early_shadow_pmd, PMD_TABLE_SIZE);
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pud_populate(&init_mm, pudp, pmdp);
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}
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pmdp = pmd_offset(pudp, ea);
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if (kasan_pte_table(*pmdp)) {
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ptep = memblock_alloc(PTE_TABLE_SIZE, PTE_TABLE_SIZE);
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memcpy(ptep, kasan_early_shadow_pte, PTE_TABLE_SIZE);
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pmd_populate_kernel(&init_mm, pmdp, ptep);
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}
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ptep = pte_offset_kernel(pmdp, ea);
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__set_pte_at(&init_mm, ea, ptep, pfn_pte(pa >> PAGE_SHIFT, prot), 0);
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return 0;
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}
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static void __init kasan_init_phys_region(void *start, void *end)
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{
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unsigned long k_start, k_end, k_cur;
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void *va;
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if (start >= end)
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return;
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k_start = ALIGN_DOWN((unsigned long)kasan_mem_to_shadow(start), PAGE_SIZE);
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k_end = ALIGN((unsigned long)kasan_mem_to_shadow(end), PAGE_SIZE);
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va = memblock_alloc(k_end - k_start, PAGE_SIZE);
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for (k_cur = k_start; k_cur < k_end; k_cur += PAGE_SIZE, va += PAGE_SIZE)
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kasan_map_kernel_page(k_cur, __pa(va), PAGE_KERNEL);
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}
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void __init kasan_early_init(void)
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{
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int i;
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unsigned long addr;
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pgd_t *pgd = pgd_offset_k(KASAN_SHADOW_START);
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pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL);
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BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_START, PGDIR_SIZE));
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BUILD_BUG_ON(!IS_ALIGNED(KASAN_SHADOW_END, PGDIR_SIZE));
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for (i = 0; i < PTRS_PER_PTE; i++)
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__set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
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&kasan_early_shadow_pte[i], zero_pte, 0);
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for (i = 0; i < PTRS_PER_PMD; i++)
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pmd_populate_kernel(&init_mm, &kasan_early_shadow_pmd[i],
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kasan_early_shadow_pte);
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for (i = 0; i < PTRS_PER_PUD; i++)
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pud_populate(&init_mm, &kasan_early_shadow_pud[i],
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kasan_early_shadow_pmd);
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for (addr = KASAN_SHADOW_START; addr != KASAN_SHADOW_END; addr += PGDIR_SIZE)
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p4d_populate(&init_mm, p4d_offset(pgd++, addr), kasan_early_shadow_pud);
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}
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void __init kasan_init(void)
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{
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phys_addr_t start, end;
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u64 i;
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pte_t zero_pte = pfn_pte(virt_to_pfn(kasan_early_shadow_page), PAGE_KERNEL_RO);
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for_each_mem_range(i, &start, &end)
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kasan_init_phys_region(phys_to_virt(start), phys_to_virt(end));
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if (IS_ENABLED(CONFIG_KASAN_VMALLOC))
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kasan_remove_zero_shadow((void *)VMALLOC_START, VMALLOC_SIZE);
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for (i = 0; i < PTRS_PER_PTE; i++)
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__set_pte_at(&init_mm, (unsigned long)kasan_early_shadow_page,
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&kasan_early_shadow_pte[i], zero_pte, 0);
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flush_tlb_kernel_range(KASAN_SHADOW_START, KASAN_SHADOW_END);
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memset(kasan_early_shadow_page, 0, PAGE_SIZE);
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/* Enable error messages */
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init_task.kasan_depth = 0;
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pr_info("KASAN init done\n");
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}
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void __init kasan_late_init(void) { }
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