99 строки
2.5 KiB
C
99 строки
2.5 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
|
|
/*
|
|
* MMU-generic set_memory implementation for powerpc
|
|
*
|
|
* Copyright 2019-2021, IBM Corporation.
|
|
*/
|
|
|
|
#include <linux/mm.h>
|
|
#include <linux/vmalloc.h>
|
|
#include <linux/set_memory.h>
|
|
|
|
#include <asm/mmu.h>
|
|
#include <asm/page.h>
|
|
#include <asm/pgtable.h>
|
|
|
|
|
|
static pte_basic_t pte_update_delta(pte_t *ptep, unsigned long addr,
|
|
unsigned long old, unsigned long new)
|
|
{
|
|
return pte_update(&init_mm, addr, ptep, old & ~new, new & ~old, 0);
|
|
}
|
|
|
|
/*
|
|
* Updates the attributes of a page atomically.
|
|
*
|
|
* This sequence is safe against concurrent updates, and also allows updating the
|
|
* attributes of a page currently being executed or accessed.
|
|
*/
|
|
static int change_page_attr(pte_t *ptep, unsigned long addr, void *data)
|
|
{
|
|
long action = (long)data;
|
|
|
|
/* modify the PTE bits as desired */
|
|
switch (action) {
|
|
case SET_MEMORY_RO:
|
|
/* Don't clear DIRTY bit */
|
|
pte_update_delta(ptep, addr, _PAGE_KERNEL_RW & ~_PAGE_DIRTY, _PAGE_KERNEL_RO);
|
|
break;
|
|
case SET_MEMORY_RW:
|
|
pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_RW);
|
|
break;
|
|
case SET_MEMORY_NX:
|
|
pte_update_delta(ptep, addr, _PAGE_KERNEL_ROX, _PAGE_KERNEL_RO);
|
|
break;
|
|
case SET_MEMORY_X:
|
|
pte_update_delta(ptep, addr, _PAGE_KERNEL_RO, _PAGE_KERNEL_ROX);
|
|
break;
|
|
case SET_MEMORY_NP:
|
|
pte_update(&init_mm, addr, ptep, _PAGE_PRESENT, 0, 0);
|
|
break;
|
|
case SET_MEMORY_P:
|
|
pte_update(&init_mm, addr, ptep, 0, _PAGE_PRESENT, 0);
|
|
break;
|
|
default:
|
|
WARN_ON_ONCE(1);
|
|
break;
|
|
}
|
|
|
|
/* See ptesync comment in radix__set_pte_at() */
|
|
if (radix_enabled())
|
|
asm volatile("ptesync": : :"memory");
|
|
|
|
flush_tlb_kernel_range(addr, addr + PAGE_SIZE);
|
|
|
|
return 0;
|
|
}
|
|
|
|
int change_memory_attr(unsigned long addr, int numpages, long action)
|
|
{
|
|
unsigned long start = ALIGN_DOWN(addr, PAGE_SIZE);
|
|
unsigned long size = numpages * PAGE_SIZE;
|
|
|
|
if (!numpages)
|
|
return 0;
|
|
|
|
if (WARN_ON_ONCE(is_vmalloc_or_module_addr((void *)addr) &&
|
|
is_vm_area_hugepages((void *)addr)))
|
|
return -EINVAL;
|
|
|
|
#ifdef CONFIG_PPC_BOOK3S_64
|
|
/*
|
|
* On hash, the linear mapping is not in the Linux page table so
|
|
* apply_to_existing_page_range() will have no effect. If in the future
|
|
* the set_memory_* functions are used on the linear map this will need
|
|
* to be updated.
|
|
*/
|
|
if (!radix_enabled()) {
|
|
int region = get_region_id(addr);
|
|
|
|
if (WARN_ON_ONCE(region != VMALLOC_REGION_ID && region != IO_REGION_ID))
|
|
return -EINVAL;
|
|
}
|
|
#endif
|
|
|
|
return apply_to_existing_page_range(&init_mm, start, size,
|
|
change_page_attr, (void *)action);
|
|
}
|