#include <asm/uaccess.h>
#include <asm/pgalloc.h>
-static DEFINE_SPINLOCK(cpa_lock);
-static struct list_head df_list = LIST_HEAD_INIT(df_list);
-
pte_t *lookup_address(unsigned long address, int *level)
{
pgd_t *pgd = pgd_offset_k(address);
pte_t *pbase;
int i;
- spin_unlock_irq(&cpa_lock);
base = alloc_pages(GFP_KERNEL, 0);
- spin_lock_irq(&cpa_lock);
if (!base)
return NULL;
* page_private is used to track the number of entries in
* the page table page that have non standard attributes.
*/
- SetPagePrivate(base);
- page_private(base) = 0;
-
address = __pa(address);
addr = address & LARGE_PAGE_MASK;
pbase = (pte_t *)page_address(base);
return base;
}
-static void cache_flush_page(struct page *p)
-{
- void *addr = page_address(p);
- int i;
-
- for (i = 0; i < PAGE_SIZE; i += boot_cpu_data.x86_clflush_size)
- clflush(addr + i);
-}
-
-static void flush_kernel_map(void *arg)
-{
- struct list_head *lh = (struct list_head *)arg;
- struct page *p;
-
- /*
- * Flush all to work around Errata in early athlons regarding
- * large page flushing.
- */
- __flush_tlb_all();
-
- /* High level code is not ready for clflush yet */
- if (0 && cpu_has_clflush) {
- list_for_each_entry(p, lh, lru)
- cache_flush_page(p);
- } else {
- if (boot_cpu_data.x86_model >= 4)
- wbinvd();
- }
-}
-
static void set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte)
{
unsigned long flags;
spin_unlock_irqrestore(&pgd_lock, flags);
}
-/*
- * No more special protections in this 2/4MB area - revert to a large
- * page again.
- */
-static inline void revert_page(struct page *kpte_page, unsigned long address)
-{
- pgprot_t ref_prot;
- pte_t *linear;
-
- ref_prot =
- ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
- ? PAGE_KERNEL_LARGE_EXEC : PAGE_KERNEL_LARGE;
-
- linear = (pte_t *)
- pmd_offset(pud_offset(pgd_offset_k(address), address), address);
- set_pmd_pte(linear, address,
- pfn_pte((__pa(address) & LARGE_PAGE_MASK) >> PAGE_SHIFT,
- ref_prot));
-}
-
-static inline void save_page(struct page *kpte_page)
-{
- if (!test_and_set_bit(PG_arch_1, &kpte_page->flags))
- list_add(&kpte_page->lru, &df_list);
-}
-
static int __change_page_attr(struct page *page, pgprot_t prot)
{
+ pgprot_t ref_prot = PAGE_KERNEL;
struct page *kpte_page;
unsigned long address;
+ pgprot_t oldprot;
pte_t *kpte;
int level;
if (!kpte)
return -EINVAL;
+ oldprot = pte_pgprot(*kpte);
kpte_page = virt_to_page(kpte);
BUG_ON(PageLRU(kpte_page));
BUG_ON(PageCompound(kpte_page));
- if (pgprot_val(prot) != pgprot_val(PAGE_KERNEL)) {
- if (level == 3) {
- set_pte_atomic(kpte, mk_pte(page, prot));
- } else {
- struct page *split;
- pgprot_t ref_prot;
-
- ref_prot =
- ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
- ? PAGE_KERNEL_EXEC : PAGE_KERNEL;
- split = split_large_page(address, prot, ref_prot);
- if (!split)
- return -ENOMEM;
-
- set_pmd_pte(kpte, address, mk_pte(split, ref_prot));
- kpte_page = split;
- }
- page_private(kpte_page)++;
- } else {
- if (level == 3) {
- set_pte_atomic(kpte, mk_pte(page, PAGE_KERNEL));
- BUG_ON(page_private(kpte_page) == 0);
- page_private(kpte_page)--;
- } else
- BUG();
- }
-
/*
- * If the pte was reserved, it means it was created at boot
- * time (not via split_large_page) and in turn we must not
- * replace it with a largepage.
+ * Better fail early if someone sets the kernel text to NX.
+ * Does not cover __inittext
*/
+ BUG_ON(address >= (unsigned long)&_text &&
+ address < (unsigned long)&_etext &&
+ (pgprot_val(prot) & _PAGE_NX));
- save_page(kpte_page);
- if (!PageReserved(kpte_page)) {
- if (cpu_has_pse && (page_private(kpte_page) == 0)) {
- paravirt_release_pt(page_to_pfn(kpte_page));
- revert_page(kpte_page, address);
- }
+ if ((address & LARGE_PAGE_MASK) < (unsigned long)&_etext)
+ ref_prot = PAGE_KERNEL_EXEC;
+
+ ref_prot = canon_pgprot(ref_prot);
+ prot = canon_pgprot(prot);
+
+ if (level == 3) {
+ set_pte_atomic(kpte, mk_pte(page, prot));
+ } else {
+ struct page *split;
+ split = split_large_page(address, prot, ref_prot);
+ if (!split)
+ return -ENOMEM;
+
+ /*
+ * There's a small window here to waste a bit of RAM:
+ */
+ set_pmd_pte(kpte, address, mk_pte(split, ref_prot));
}
return 0;
}
-static inline void flush_map(struct list_head *l)
-{
- on_each_cpu(flush_kernel_map, l, 1, 1);
-}
-
/*
* Change the page attributes of an page in the linear mapping.
*
*/
int change_page_attr(struct page *page, int numpages, pgprot_t prot)
{
- unsigned long flags;
int err = 0, i;
- spin_lock_irqsave(&cpa_lock, flags);
for (i = 0; i < numpages; i++, page++) {
err = __change_page_attr(page, prot);
if (err)
break;
}
- spin_unlock_irqrestore(&cpa_lock, flags);
return err;
}
EXPORT_SYMBOL(change_page_attr);
-void global_flush_tlb(void)
+int change_page_attr_addr(unsigned long addr, int numpages, pgprot_t prot)
{
- struct page *pg, *next;
- struct list_head l;
+ int i;
+ unsigned long pfn = (addr >> PAGE_SHIFT);
+ for (i = 0; i < numpages; i++) {
+ if (!pfn_valid(pfn + i)) {
+ break;
+ } else {
+ int level;
+ pte_t *pte = lookup_address(addr + i*PAGE_SIZE, &level);
+ BUG_ON(pte && !pte_none(*pte));
+ }
+ }
+ return change_page_attr(virt_to_page(addr), i, prot);
+}
+
+static void flush_kernel_map(void *arg)
+{
+ /*
+ * Flush all to work around Errata in early athlons regarding
+ * large page flushing.
+ */
+ __flush_tlb_all();
+
+ if (boot_cpu_data.x86_model >= 4)
+ wbinvd();
+}
+
+void global_flush_tlb(void)
+{
BUG_ON(irqs_disabled());
- spin_lock_irq(&cpa_lock);
- list_replace_init(&df_list, &l);
- spin_unlock_irq(&cpa_lock);
- flush_map(&l);
- list_for_each_entry_safe(pg, next, &l, lru) {
- list_del(&pg->lru);
- clear_bit(PG_arch_1, &pg->flags);
- if (PageReserved(pg) || !cpu_has_pse || page_private(pg) != 0)
- continue;
- ClearPagePrivate(pg);
- __free_page(pg);
- }
+ on_each_cpu(flush_kernel_map, NULL, 1, 1);
}
EXPORT_SYMBOL(global_flush_tlb);
projects / linux-beck.git / commitdiff