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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2000 - 2007 Jeff Dike (jdike@{addtoit,linux.intel}.com)
*/
#include <linux/stddef.h>
#include <linux/module.h>
#include <linux/memblock.h>
#include <linux/mm.h>
#include <linux/swap.h>
#include <linux/slab.h>
#include <linux/init.h>
#include <asm/sections.h>
#include <asm/page.h>
#include <asm/pgalloc.h>
#include <as-layout.h>
#include <init.h>
#include <kern.h>
#include <kern_util.h>
#include <mem_user.h>
#include <os.h>
#include <um_malloc.h>
#include <linux/sched/task.h>
#include <linux/kasan.h>
#ifdef CONFIG_KASAN
void __init kasan_init(void)
{
/*
* kasan_map_memory will map all of the required address space and
* the host machine will allocate physical memory as necessary.
*/
kasan_map_memory((void *)KASAN_SHADOW_START, KASAN_SHADOW_SIZE);
init_task.kasan_depth = 0;
/*
* Since kasan_init() is called before main(),
* KASAN is initialized but the enablement is deferred after
* jump_label_init(). See arch_mm_preinit().
*/
}
static void (*kasan_init_ptr)(void)
__section(".kasan_init") __used
= kasan_init;
#endif
/* allocated in paging_init, zeroed in mem_init, and unchanged thereafter */
unsigned long *empty_zero_page = NULL;
EXPORT_SYMBOL(empty_zero_page);
/*
* Initialized during boot, and readonly for initializing page tables
* afterwards
*/
pgd_t swapper_pg_dir[PTRS_PER_PGD];
/* Initialized at boot time, and readonly after that */
int kmalloc_ok = 0;
/* Used during early boot */
static unsigned long brk_end;
void __init arch_mm_preinit(void)
{
/* Safe to call after jump_label_init(). Enables KASAN. */
kasan_init_generic();
/* clear the zero-page */
memset(empty_zero_page, 0, PAGE_SIZE);
/* Map in the area just after the brk now that kmalloc is about
* to be turned on.
*/
brk_end = PAGE_ALIGN((unsigned long) sbrk(0));
map_memory(brk_end, __pa(brk_end), uml_reserved - brk_end, 1, 1, 0);
memblock_free((void *)brk_end, uml_reserved - brk_end);
uml_reserved = brk_end;
min_low_pfn = PFN_UP(__pa(uml_reserved));
max_pfn = max_low_pfn;
}
void __init mem_init(void)
{
kmalloc_ok = 1;
}
void __init paging_init(void)
{
unsigned long max_zone_pfn[MAX_NR_ZONES] = { 0 };
empty_zero_page = (unsigned long *) memblock_alloc_low(PAGE_SIZE,
PAGE_SIZE);
if (!empty_zero_page)
panic("%s: Failed to allocate %lu bytes align=%lx\n",
__func__, PAGE_SIZE, PAGE_SIZE);
max_zone_pfn[ZONE_NORMAL] = high_physmem >> PAGE_SHIFT;
free_area_init(max_zone_pfn);
}
/*
* This can't do anything because nothing in the kernel image can be freed
* since it's not in kernel physical memory.
*/
void free_initmem(void)
{
}
/* Allocate and free page tables. */
pgd_t *pgd_alloc(struct mm_struct *mm)
{
pgd_t *pgd = __pgd_alloc(mm, 0);
if (pgd)
memcpy(pgd + USER_PTRS_PER_PGD,
swapper_pg_dir + USER_PTRS_PER_PGD,
(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
return pgd;
}
void *uml_kmalloc(int size, int flags)
{
return kmalloc(size, flags);
}
static const pgprot_t protection_map[16] = {
[VM_NONE] = PAGE_NONE,
[VM_READ] = PAGE_READONLY,
[VM_WRITE] = PAGE_COPY,
[VM_WRITE | VM_READ] = PAGE_COPY,
[VM_EXEC] = PAGE_READONLY,
[VM_EXEC | VM_READ] = PAGE_READONLY,
[VM_EXEC | VM_WRITE] = PAGE_COPY,
[VM_EXEC | VM_WRITE | VM_READ] = PAGE_COPY,
[VM_SHARED] = PAGE_NONE,
[VM_SHARED | VM_READ] = PAGE_READONLY,
[VM_SHARED | VM_WRITE] = PAGE_SHARED,
[VM_SHARED | VM_WRITE | VM_READ] = PAGE_SHARED,
[VM_SHARED | VM_EXEC] = PAGE_READONLY,
[VM_SHARED | VM_EXEC | VM_READ] = PAGE_READONLY,
[VM_SHARED | VM_EXEC | VM_WRITE] = PAGE_SHARED,
[VM_SHARED | VM_EXEC | VM_WRITE | VM_READ] = PAGE_SHARED
};
DECLARE_VM_GET_PAGE_PROT
void mark_rodata_ro(void)
{
unsigned long rodata_start = PFN_ALIGN(__start_rodata);
unsigned long rodata_end = PFN_ALIGN(__end_rodata);
os_protect_memory((void *)rodata_start, rodata_end - rodata_start, 1, 0, 0);
}
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