arch/powerpc/mm/kasan/init_32.c

Source file repositories/reference/linux-study-clean/arch/powerpc/mm/kasan/init_32.c

File Facts

System
Linux kernel
Corpus path
arch/powerpc/mm/kasan/init_32.c
Extension
.c
Size
4751 bytes
Lines
193
Domain
Architecture Layer
Bucket
arch/powerpc
Inferred role
Architecture Layer: implementation source
Status
source implementation candidate

Why This File Exists

CPU and platform-specific kernel glue: boot entry, traps, syscall entry, interrupts, page tables, context switch, and low-level barriers.

Dependency Surface

Detected Declarations

Annotated Snippet

// SPDX-License-Identifier: GPL-2.0

#define DISABLE_BRANCH_PROFILING

#include <linux/kasan.h>
#include <linux/printk.h>
#include <linux/memblock.h>
#include <linux/sched/task.h>
#include <asm/pgalloc.h>
#include <asm/text-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), 1);
}

int __init kasan_init_shadow_page_tables(unsigned long k_start, unsigned long k_end)
{
	pmd_t *pmd;
	unsigned long k_cur, k_next;

	pmd = pmd_off_k(k_start);

	for (k_cur = k_start; k_cur != k_end; k_cur = k_next, pmd++) {
		pte_t *new;

		k_next = pgd_addr_end(k_cur, k_end);
		if ((void *)pmd_page_vaddr(*pmd) != kasan_early_shadow_pte)
			continue;

		new = memblock_alloc(PTE_FRAG_SIZE, PTE_FRAG_SIZE);

		if (!new)
			return -ENOMEM;
		kasan_populate_pte(new, PAGE_KERNEL);
		pmd_populate_kernel(&init_mm, pmd, new);
	}
	return 0;
}

int __init __weak 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;

	k_start = k_start & PAGE_MASK;
	block = memblock_alloc(k_end - k_start, PAGE_SIZE);
	if (!block)
		return -ENOMEM;

	for (k_cur = k_start & PAGE_MASK; k_cur < k_end; k_cur += PAGE_SIZE) {
		pmd_t *pmd = pmd_off_k(k_cur);
		void *va = block + k_cur - k_start;
		pte_t pte = pfn_pte(PHYS_PFN(__pa(va)), PAGE_KERNEL);

		__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;
}

void __init
kasan_update_early_region(unsigned long k_start, unsigned long k_end, pte_t pte)
{
	unsigned long k_cur;

	for (k_cur = k_start; k_cur != k_end; k_cur += PAGE_SIZE) {
		pmd_t *pmd = pmd_off_k(k_cur);
		pte_t *ptep = pte_offset_kernel(pmd, k_cur);

Annotation

Implementation Notes