Contributors: 28
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Laura Abbott |
502 |
38.91% |
5 |
12.20% |
| Ard Biesheuvel |
255 |
19.77% |
4 |
9.76% |
| Suzuki K. Poulose |
236 |
18.29% |
1 |
2.44% |
| James Morse |
116 |
8.99% |
2 |
4.88% |
| Mike Rapoport |
56 |
4.34% |
5 |
12.20% |
| Will Deacon |
40 |
3.10% |
2 |
4.88% |
| AKASHI Takahiro |
18 |
1.40% |
1 |
2.44% |
| Steven Price |
10 |
0.78% |
1 |
2.44% |
| Mika Penttilä |
8 |
0.62% |
1 |
2.44% |
| Michael Ellerman |
7 |
0.54% |
1 |
2.44% |
| Tang Chen |
4 |
0.31% |
1 |
2.44% |
| Andrey Konovalov |
3 |
0.23% |
1 |
2.44% |
| Johannes Weiner |
3 |
0.23% |
1 |
2.44% |
| Catalin Marinas |
3 |
0.23% |
1 |
2.44% |
| Tian Tao |
3 |
0.23% |
1 |
2.44% |
| Stanislaw Gruszka |
3 |
0.23% |
1 |
2.44% |
| Mark Rutland |
3 |
0.23% |
1 |
2.44% |
| Alexander Potapenko |
3 |
0.23% |
1 |
2.44% |
| Ryan Roberts |
3 |
0.23% |
1 |
2.44% |
| Ingo Molnar |
2 |
0.16% |
1 |
2.44% |
| Mark Brown |
2 |
0.16% |
1 |
2.44% |
| Thomas Gleixner |
2 |
0.16% |
1 |
2.44% |
| Zhenhua HUANG |
2 |
0.16% |
1 |
2.44% |
| Robin Murphy |
2 |
0.16% |
1 |
2.44% |
| Andrew Morton |
1 |
0.08% |
1 |
2.44% |
| Kefeng Wang |
1 |
0.08% |
1 |
2.44% |
| Alexander Kuleshov |
1 |
0.08% |
1 |
2.44% |
| Linus Torvalds |
1 |
0.08% |
1 |
2.44% |
| Total |
1290 |
|
41 |
|
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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (c) 2014, The Linux Foundation. All rights reserved.
*/
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mem_encrypt.h>
#include <linux/sched.h>
#include <linux/vmalloc.h>
#include <asm/cacheflush.h>
#include <asm/pgtable-prot.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <asm/kfence.h>
struct page_change_data {
pgprot_t set_mask;
pgprot_t clear_mask;
};
bool rodata_full __ro_after_init = IS_ENABLED(CONFIG_RODATA_FULL_DEFAULT_ENABLED);
bool can_set_direct_map(void)
{
/*
* rodata_full, DEBUG_PAGEALLOC and a Realm guest all require linear
* map to be mapped at page granularity, so that it is possible to
* protect/unprotect single pages.
*
* KFENCE pool requires page-granular mapping if initialized late.
*
* Realms need to make pages shared/protected at page granularity.
*/
return rodata_full || debug_pagealloc_enabled() ||
arm64_kfence_can_set_direct_map() || is_realm_world();
}
static int change_page_range(pte_t *ptep, unsigned long addr, void *data)
{
struct page_change_data *cdata = data;
pte_t pte = __ptep_get(ptep);
pte = clear_pte_bit(pte, cdata->clear_mask);
pte = set_pte_bit(pte, cdata->set_mask);
__set_pte(ptep, pte);
return 0;
}
/*
* This function assumes that the range is mapped with PAGE_SIZE pages.
*/
static int __change_memory_common(unsigned long start, unsigned long size,
pgprot_t set_mask, pgprot_t clear_mask)
{
struct page_change_data data;
int ret;
data.set_mask = set_mask;
data.clear_mask = clear_mask;
ret = apply_to_page_range(&init_mm, start, size, change_page_range,
&data);
/*
* If the memory is being made valid without changing any other bits
* then a TLBI isn't required as a non-valid entry cannot be cached in
* the TLB.
*/
if (pgprot_val(set_mask) != PTE_VALID || pgprot_val(clear_mask))
flush_tlb_kernel_range(start, start + size);
return ret;
}
static int change_memory_common(unsigned long addr, int numpages,
pgprot_t set_mask, pgprot_t clear_mask)
{
unsigned long start = addr;
unsigned long size = PAGE_SIZE * numpages;
unsigned long end = start + size;
struct vm_struct *area;
int i;
if (!PAGE_ALIGNED(addr)) {
start &= PAGE_MASK;
end = start + size;
WARN_ON_ONCE(1);
}
/*
* Kernel VA mappings are always live, and splitting live section
* mappings into page mappings may cause TLB conflicts. This means
* we have to ensure that changing the permission bits of the range
* we are operating on does not result in such splitting.
*
* Let's restrict ourselves to mappings created by vmalloc (or vmap).
* Those are guaranteed to consist entirely of page mappings, and
* splitting is never needed.
*
* So check whether the [addr, addr + size) interval is entirely
* covered by precisely one VM area that has the VM_ALLOC flag set.
*/
area = find_vm_area((void *)addr);
if (!area ||
end > (unsigned long)kasan_reset_tag(area->addr) + area->size ||
!(area->flags & VM_ALLOC))
return -EINVAL;
if (!numpages)
return 0;
/*
* If we are manipulating read-only permissions, apply the same
* change to the linear mapping of the pages that back this VM area.
*/
if (rodata_full && (pgprot_val(set_mask) == PTE_RDONLY ||
pgprot_val(clear_mask) == PTE_RDONLY)) {
for (i = 0; i < area->nr_pages; i++) {
__change_memory_common((u64)page_address(area->pages[i]),
PAGE_SIZE, set_mask, clear_mask);
}
}
/*
* Get rid of potentially aliasing lazily unmapped vm areas that may
* have permissions set that deviate from the ones we are setting here.
*/
vm_unmap_aliases();
return __change_memory_common(start, size, set_mask, clear_mask);
}
int set_memory_ro(unsigned long addr, int numpages)
{
return change_memory_common(addr, numpages,
__pgprot(PTE_RDONLY),
__pgprot(PTE_WRITE));
}
int set_memory_rw(unsigned long addr, int numpages)
{
return change_memory_common(addr, numpages,
__pgprot(PTE_WRITE),
__pgprot(PTE_RDONLY));
}
int set_memory_nx(unsigned long addr, int numpages)
{
return change_memory_common(addr, numpages,
__pgprot(PTE_PXN),
__pgprot(PTE_MAYBE_GP));
}
int set_memory_x(unsigned long addr, int numpages)
{
return change_memory_common(addr, numpages,
__pgprot(PTE_MAYBE_GP),
__pgprot(PTE_PXN));
}
int set_memory_valid(unsigned long addr, int numpages, int enable)
{
if (enable)
return __change_memory_common(addr, PAGE_SIZE * numpages,
__pgprot(PTE_VALID),
__pgprot(0));
else
return __change_memory_common(addr, PAGE_SIZE * numpages,
__pgprot(0),
__pgprot(PTE_VALID));
}
int set_direct_map_invalid_noflush(struct page *page)
{
struct page_change_data data = {
.set_mask = __pgprot(0),
.clear_mask = __pgprot(PTE_VALID),
};
if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
(unsigned long)page_address(page),
PAGE_SIZE, change_page_range, &data);
}
int set_direct_map_default_noflush(struct page *page)
{
struct page_change_data data = {
.set_mask = __pgprot(PTE_VALID | PTE_WRITE),
.clear_mask = __pgprot(PTE_RDONLY),
};
if (!can_set_direct_map())
return 0;
return apply_to_page_range(&init_mm,
(unsigned long)page_address(page),
PAGE_SIZE, change_page_range, &data);
}
static int __set_memory_enc_dec(unsigned long addr,
int numpages,
bool encrypt)
{
unsigned long set_prot = 0, clear_prot = 0;
phys_addr_t start, end;
int ret;
if (!is_realm_world())
return 0;
if (!__is_lm_address(addr))
return -EINVAL;
start = __virt_to_phys(addr);
end = start + numpages * PAGE_SIZE;
if (encrypt)
clear_prot = PROT_NS_SHARED;
else
set_prot = PROT_NS_SHARED;
/*
* Break the mapping before we make any changes to avoid stale TLB
* entries or Synchronous External Aborts caused by RIPAS_EMPTY
*/
ret = __change_memory_common(addr, PAGE_SIZE * numpages,
__pgprot(set_prot),
__pgprot(clear_prot | PTE_VALID));
if (ret)
return ret;
if (encrypt)
ret = rsi_set_memory_range_protected(start, end);
else
ret = rsi_set_memory_range_shared(start, end);
if (ret)
return ret;
return __change_memory_common(addr, PAGE_SIZE * numpages,
__pgprot(PTE_VALID),
__pgprot(0));
}
static int realm_set_memory_encrypted(unsigned long addr, int numpages)
{
int ret = __set_memory_enc_dec(addr, numpages, true);
/*
* If the request to change state fails, then the only sensible cause
* of action for the caller is to leak the memory
*/
WARN(ret, "Failed to encrypt memory, %d pages will be leaked",
numpages);
return ret;
}
static int realm_set_memory_decrypted(unsigned long addr, int numpages)
{
int ret = __set_memory_enc_dec(addr, numpages, false);
WARN(ret, "Failed to decrypt memory, %d pages will be leaked",
numpages);
return ret;
}
static const struct arm64_mem_crypt_ops realm_crypt_ops = {
.encrypt = realm_set_memory_encrypted,
.decrypt = realm_set_memory_decrypted,
};
int realm_register_memory_enc_ops(void)
{
return arm64_mem_crypt_ops_register(&realm_crypt_ops);
}
int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid)
{
unsigned long addr = (unsigned long)page_address(page);
if (!can_set_direct_map())
return 0;
return set_memory_valid(addr, nr, valid);
}
#ifdef CONFIG_DEBUG_PAGEALLOC
/*
* This is - apart from the return value - doing the same
* thing as the new set_direct_map_valid_noflush() function.
*
* Unify? Explain the conceptual differences?
*/
void __kernel_map_pages(struct page *page, int numpages, int enable)
{
if (!can_set_direct_map())
return;
set_memory_valid((unsigned long)page_address(page), numpages, enable);
}
#endif /* CONFIG_DEBUG_PAGEALLOC */
/*
* This function is used to determine if a linear map page has been marked as
* not-valid. Walk the page table and check the PTE_VALID bit.
*
* Because this is only called on the kernel linear map, p?d_sect() implies
* p?d_present(). When debug_pagealloc is enabled, sections mappings are
* disabled.
*/
bool kernel_page_present(struct page *page)
{
pgd_t *pgdp;
p4d_t *p4dp;
pud_t *pudp, pud;
pmd_t *pmdp, pmd;
pte_t *ptep;
unsigned long addr = (unsigned long)page_address(page);
pgdp = pgd_offset_k(addr);
if (pgd_none(READ_ONCE(*pgdp)))
return false;
p4dp = p4d_offset(pgdp, addr);
if (p4d_none(READ_ONCE(*p4dp)))
return false;
pudp = pud_offset(p4dp, addr);
pud = READ_ONCE(*pudp);
if (pud_none(pud))
return false;
if (pud_sect(pud))
return true;
pmdp = pmd_offset(pudp, addr);
pmd = READ_ONCE(*pmdp);
if (pmd_none(pmd))
return false;
if (pmd_sect(pmd))
return true;
ptep = pte_offset_kernel(pmdp, addr);
return pte_valid(__ptep_get(ptep));
}