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Diffstat (limited to 'arch/x86/mm/pat/set_memory.c')
-rw-r--r--arch/x86/mm/pat/set_memory.c105
1 files changed, 71 insertions, 34 deletions
diff --git a/arch/x86/mm/pat/set_memory.c b/arch/x86/mm/pat/set_memory.c
index ef34ba21aa92..356758b7d4b4 100644
--- a/arch/x86/mm/pat/set_memory.c
+++ b/arch/x86/mm/pat/set_memory.c
@@ -220,6 +220,23 @@ within_inclusive(unsigned long addr, unsigned long start, unsigned long end)
#ifdef CONFIG_X86_64
+/*
+ * The kernel image is mapped into two places in the virtual address space
+ * (addresses without KASLR, of course):
+ *
+ * 1. The kernel direct map (0xffff880000000000)
+ * 2. The "high kernel map" (0xffffffff81000000)
+ *
+ * We actually execute out of #2. If we get the address of a kernel symbol, it
+ * points to #2, but almost all physical-to-virtual translations point to #1.
+ *
+ * This is so that we can have both a directmap of all physical memory *and*
+ * take full advantage of the the limited (s32) immediate addressing range (2G)
+ * of x86_64.
+ *
+ * See Documentation/x86/x86_64/mm.rst for more detail.
+ */
+
static inline unsigned long highmap_start_pfn(void)
{
return __pa_symbol(_text) >> PAGE_SHIFT;
@@ -605,10 +622,6 @@ static inline pgprot_t verify_rwx(pgprot_t old, pgprot_t new, unsigned long star
{
unsigned long end;
- /* Kernel text is rw at boot up */
- if (system_state == SYSTEM_BOOTING)
- return new;
-
/*
* 32-bit has some unfixable W+X issues, like EFI code
* and writeable data being in the same page. Disable
@@ -765,11 +778,11 @@ phys_addr_t slow_virt_to_phys(void *__virt_addr)
switch (level) {
case PG_LEVEL_1G:
phys_addr = (phys_addr_t)pud_pfn(*(pud_t *)pte) << PAGE_SHIFT;
- offset = virt_addr & ~PUD_PAGE_MASK;
+ offset = virt_addr & ~PUD_MASK;
break;
case PG_LEVEL_2M:
phys_addr = (phys_addr_t)pmd_pfn(*(pmd_t *)pte) << PAGE_SHIFT;
- offset = virt_addr & ~PMD_PAGE_MASK;
+ offset = virt_addr & ~PMD_MASK;
break;
default:
phys_addr = (phys_addr_t)pte_pfn(*pte) << PAGE_SHIFT;
@@ -1059,7 +1072,7 @@ __split_large_page(struct cpa_data *cpa, pte_t *kpte, unsigned long address,
case PG_LEVEL_1G:
ref_prot = pud_pgprot(*(pud_t *)kpte);
ref_pfn = pud_pfn(*(pud_t *)kpte);
- pfninc = PMD_PAGE_SIZE >> PAGE_SHIFT;
+ pfninc = PMD_SIZE >> PAGE_SHIFT;
lpaddr = address & PUD_MASK;
lpinc = PMD_SIZE;
/*
@@ -1646,8 +1659,11 @@ repeat:
return err;
}
-static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias);
+static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary);
+/*
+ * Check the directmap and "high kernel map" 'aliases'.
+ */
static int cpa_process_alias(struct cpa_data *cpa)
{
struct cpa_data alias_cpa;
@@ -1671,6 +1687,12 @@ static int cpa_process_alias(struct cpa_data *cpa)
alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
alias_cpa.curpage = 0;
+ /* Directmap always has NX set, do not modify. */
+ if (__supported_pte_mask & _PAGE_NX) {
+ alias_cpa.mask_clr.pgprot &= ~_PAGE_NX;
+ alias_cpa.mask_set.pgprot &= ~_PAGE_NX;
+ }
+
cpa->force_flush_all = 1;
ret = __change_page_attr_set_clr(&alias_cpa, 0);
@@ -1693,6 +1715,15 @@ static int cpa_process_alias(struct cpa_data *cpa)
alias_cpa.flags &= ~(CPA_PAGES_ARRAY | CPA_ARRAY);
alias_cpa.curpage = 0;
+ /*
+ * [_text, _brk_end) also covers data, do not modify NX except
+ * in cases where the highmap is the primary target.
+ */
+ if (__supported_pte_mask & _PAGE_NX) {
+ alias_cpa.mask_clr.pgprot &= ~_PAGE_NX;
+ alias_cpa.mask_set.pgprot &= ~_PAGE_NX;
+ }
+
cpa->force_flush_all = 1;
/*
* The high mapping range is imprecise, so ignore the
@@ -1705,12 +1736,19 @@ static int cpa_process_alias(struct cpa_data *cpa)
return 0;
}
-static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
+static int __change_page_attr_set_clr(struct cpa_data *cpa, int primary)
{
unsigned long numpages = cpa->numpages;
unsigned long rempages = numpages;
int ret = 0;
+ /*
+ * No changes, easy!
+ */
+ if (!(pgprot_val(cpa->mask_set) | pgprot_val(cpa->mask_clr)) &&
+ !cpa->force_split)
+ return ret;
+
while (rempages) {
/*
* Store the remaining nr of pages for the large page
@@ -1723,13 +1761,13 @@ static int __change_page_attr_set_clr(struct cpa_data *cpa, int checkalias)
if (!debug_pagealloc_enabled())
spin_lock(&cpa_lock);
- ret = __change_page_attr(cpa, checkalias);
+ ret = __change_page_attr(cpa, primary);
if (!debug_pagealloc_enabled())
spin_unlock(&cpa_lock);
if (ret)
goto out;
- if (checkalias) {
+ if (primary && !(cpa->flags & CPA_NO_CHECK_ALIAS)) {
ret = cpa_process_alias(cpa);
if (ret)
goto out;
@@ -1757,7 +1795,7 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
struct page **pages)
{
struct cpa_data cpa;
- int ret, cache, checkalias;
+ int ret, cache;
memset(&cpa, 0, sizeof(cpa));
@@ -1803,20 +1841,11 @@ static int change_page_attr_set_clr(unsigned long *addr, int numpages,
cpa.numpages = numpages;
cpa.mask_set = mask_set;
cpa.mask_clr = mask_clr;
- cpa.flags = 0;
+ cpa.flags = in_flag;
cpa.curpage = 0;
cpa.force_split = force_split;
- if (in_flag & (CPA_ARRAY | CPA_PAGES_ARRAY))
- cpa.flags |= in_flag;
-
- /* No alias checking for _NX bit modifications */
- checkalias = (pgprot_val(mask_set) | pgprot_val(mask_clr)) != _PAGE_NX;
- /* Has caller explicitly disabled alias checking? */
- if (in_flag & CPA_NO_CHECK_ALIAS)
- checkalias = 0;
-
- ret = __change_page_attr_set_clr(&cpa, checkalias);
+ ret = __change_page_attr_set_clr(&cpa, 1);
/*
* Check whether we really changed something:
@@ -2047,6 +2076,16 @@ int set_memory_ro(unsigned long addr, int numpages)
return change_page_attr_clear(&addr, numpages, __pgprot(_PAGE_RW), 0);
}
+int set_memory_rox(unsigned long addr, int numpages)
+{
+ pgprot_t clr = __pgprot(_PAGE_RW);
+
+ if (__supported_pte_mask & _PAGE_NX)
+ clr.pgprot |= _PAGE_NX;
+
+ return change_page_attr_clear(&addr, numpages, clr, 0);
+}
+
int set_memory_rw(unsigned long addr, int numpages)
{
return change_page_attr_set(&addr, numpages, __pgprot(_PAGE_RW), 0);
@@ -2059,11 +2098,9 @@ int set_memory_np(unsigned long addr, int numpages)
int set_memory_np_noalias(unsigned long addr, int numpages)
{
- int cpa_flags = CPA_NO_CHECK_ALIAS;
-
return change_page_attr_set_clr(&addr, numpages, __pgprot(0),
__pgprot(_PAGE_PRESENT), 0,
- cpa_flags, NULL);
+ CPA_NO_CHECK_ALIAS, NULL);
}
int set_memory_4k(unsigned long addr, int numpages)
@@ -2280,7 +2317,7 @@ static int __set_pages_p(struct page *page, int numpages)
.numpages = numpages,
.mask_set = __pgprot(_PAGE_PRESENT | _PAGE_RW),
.mask_clr = __pgprot(0),
- .flags = 0};
+ .flags = CPA_NO_CHECK_ALIAS };
/*
* No alias checking needed for setting present flag. otherwise,
@@ -2288,7 +2325,7 @@ static int __set_pages_p(struct page *page, int numpages)
* mappings (this adds to complexity if we want to do this from
* atomic context especially). Let's keep it simple!
*/
- return __change_page_attr_set_clr(&cpa, 0);
+ return __change_page_attr_set_clr(&cpa, 1);
}
static int __set_pages_np(struct page *page, int numpages)
@@ -2299,7 +2336,7 @@ static int __set_pages_np(struct page *page, int numpages)
.numpages = numpages,
.mask_set = __pgprot(0),
.mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
- .flags = 0};
+ .flags = CPA_NO_CHECK_ALIAS };
/*
* No alias checking needed for setting not present flag. otherwise,
@@ -2307,7 +2344,7 @@ static int __set_pages_np(struct page *page, int numpages)
* mappings (this adds to complexity if we want to do this from
* atomic context especially). Let's keep it simple!
*/
- return __change_page_attr_set_clr(&cpa, 0);
+ return __change_page_attr_set_clr(&cpa, 1);
}
int set_direct_map_invalid_noflush(struct page *page)
@@ -2378,7 +2415,7 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
.numpages = numpages,
.mask_set = __pgprot(0),
.mask_clr = __pgprot(~page_flags & (_PAGE_NX|_PAGE_RW)),
- .flags = 0,
+ .flags = CPA_NO_CHECK_ALIAS,
};
WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
@@ -2391,7 +2428,7 @@ int __init kernel_map_pages_in_pgd(pgd_t *pgd, u64 pfn, unsigned long address,
cpa.mask_set = __pgprot(_PAGE_PRESENT | page_flags);
- retval = __change_page_attr_set_clr(&cpa, 0);
+ retval = __change_page_attr_set_clr(&cpa, 1);
__flush_tlb_all();
out:
@@ -2421,12 +2458,12 @@ int __init kernel_unmap_pages_in_pgd(pgd_t *pgd, unsigned long address,
.numpages = numpages,
.mask_set = __pgprot(0),
.mask_clr = __pgprot(_PAGE_PRESENT | _PAGE_RW),
- .flags = 0,
+ .flags = CPA_NO_CHECK_ALIAS,
};
WARN_ONCE(num_online_cpus() > 1, "Don't call after initializing SMP");
- retval = __change_page_attr_set_clr(&cpa, 0);
+ retval = __change_page_attr_set_clr(&cpa, 1);
__flush_tlb_all();
return retval;
generated by cgit v1.2.3 (git 2.39.0) at 2024-08-17 01:00:11 +0300