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-rw-r--r--mm/memory.c107
1 files changed, 39 insertions, 68 deletions
diff --git a/mm/memory.c b/mm/memory.c
index d209f745db7..2405289dfdf 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -58,7 +58,7 @@
#include <linux/swapops.h>
#include <linux/elf.h>
-#ifndef CONFIG_DISCONTIGMEM
+#ifndef CONFIG_NEED_MULTIPLE_NODES
/* use the per-pgdat data instead for discontigmem - mbligh */
unsigned long max_mapnr;
struct page *mem_map;
@@ -776,8 +776,8 @@ unsigned long zap_page_range(struct vm_area_struct *vma, unsigned long address,
* Do a quick page-table lookup for a single page.
* mm->page_table_lock must be held.
*/
-static struct page *
-__follow_page(struct mm_struct *mm, unsigned long address, int read, int write)
+static struct page *__follow_page(struct mm_struct *mm, unsigned long address,
+ int read, int write, int accessed)
{
pgd_t *pgd;
pud_t *pud;
@@ -811,16 +811,15 @@ __follow_page(struct mm_struct *mm, unsigned long address, int read, int write)
pte = *ptep;
pte_unmap(ptep);
if (pte_present(pte)) {
- if (write && !pte_write(pte))
+ if (write && !pte_dirty(pte))
goto out;
if (read && !pte_read(pte))
goto out;
pfn = pte_pfn(pte);
if (pfn_valid(pfn)) {
page = pfn_to_page(pfn);
- if (write && !pte_dirty(pte) && !PageDirty(page))
- set_page_dirty(page);
- mark_page_accessed(page);
+ if (accessed)
+ mark_page_accessed(page);
return page;
}
}
@@ -829,33 +828,21 @@ out:
return NULL;
}
-struct page *
+inline struct page *
follow_page(struct mm_struct *mm, unsigned long address, int write)
{
- return __follow_page(mm, address, /*read*/0, write);
-}
-
-int
-check_user_page_readable(struct mm_struct *mm, unsigned long address)
-{
- return __follow_page(mm, address, /*read*/1, /*write*/0) != NULL;
+ return __follow_page(mm, address, 0, write, 1);
}
-EXPORT_SYMBOL(check_user_page_readable);
-
-/*
- * Given a physical address, is there a useful struct page pointing to
- * it? This may become more complex in the future if we start dealing
- * with IO-aperture pages for direct-IO.
+/*
+ * check_user_page_readable() can be called frm niterrupt context by oprofile,
+ * so we need to avoid taking any non-irq-safe locks
*/
-
-static inline struct page *get_page_map(struct page *page)
+int check_user_page_readable(struct mm_struct *mm, unsigned long address)
{
- if (!pfn_valid(page_to_pfn(page)))
- return NULL;
- return page;
+ return __follow_page(mm, address, 1, 0, 0) != NULL;
}
-
+EXPORT_SYMBOL(check_user_page_readable);
static inline int
untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma,
@@ -887,7 +874,6 @@ untouched_anonymous_page(struct mm_struct* mm, struct vm_area_struct *vma,
return 0;
}
-
int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
unsigned long start, int len, int write, int force,
struct page **pages, struct vm_area_struct **vmas)
@@ -924,9 +910,13 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
pud = pud_offset(pgd, pg);
BUG_ON(pud_none(*pud));
pmd = pmd_offset(pud, pg);
- BUG_ON(pmd_none(*pmd));
+ if (pmd_none(*pmd))
+ return i ? : -EFAULT;
pte = pte_offset_map(pmd, pg);
- BUG_ON(pte_none(*pte));
+ if (pte_none(*pte)) {
+ pte_unmap(pte);
+ return i ? : -EFAULT;
+ }
if (pages) {
pages[i] = pte_page(*pte);
get_page(pages[i]);
@@ -951,21 +941,19 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
}
spin_lock(&mm->page_table_lock);
do {
- struct page *map;
- int lookup_write = write;
+ struct page *page;
cond_resched_lock(&mm->page_table_lock);
- while (!(map = follow_page(mm, start, lookup_write))) {
+ while (!(page = follow_page(mm, start, write))) {
/*
* Shortcut for anonymous pages. We don't want
* to force the creation of pages tables for
- * insanly big anonymously mapped areas that
+ * insanely big anonymously mapped areas that
* nobody touched so far. This is important
* for doing a core dump for these mappings.
*/
- if (!lookup_write &&
- untouched_anonymous_page(mm,vma,start)) {
- map = ZERO_PAGE(start);
+ if (!write && untouched_anonymous_page(mm,vma,start)) {
+ page = ZERO_PAGE(start);
break;
}
spin_unlock(&mm->page_table_lock);
@@ -983,41 +971,24 @@ int get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
default:
BUG();
}
- /*
- * Now that we have performed a write fault
- * and surely no longer have a shared page we
- * shouldn't write, we shouldn't ignore an
- * unwritable page in the page table if
- * we are forcing write access.
- */
- lookup_write = write && !force;
spin_lock(&mm->page_table_lock);
}
if (pages) {
- pages[i] = get_page_map(map);
- if (!pages[i]) {
- spin_unlock(&mm->page_table_lock);
- while (i--)
- page_cache_release(pages[i]);
- i = -EFAULT;
- goto out;
- }
- flush_dcache_page(pages[i]);
- if (!PageReserved(pages[i]))
- page_cache_get(pages[i]);
+ pages[i] = page;
+ flush_dcache_page(page);
+ if (!PageReserved(page))
+ page_cache_get(page);
}
if (vmas)
vmas[i] = vma;
i++;
start += PAGE_SIZE;
len--;
- } while(len && start < vma->vm_end);
+ } while (len && start < vma->vm_end);
spin_unlock(&mm->page_table_lock);
- } while(len);
-out:
+ } while (len);
return i;
}
-
EXPORT_SYMBOL(get_user_pages);
static int zeromap_pte_range(struct mm_struct *mm, pmd_t *pmd,
@@ -1164,7 +1135,7 @@ int remap_pfn_range(struct vm_area_struct *vma, unsigned long addr,
{
pgd_t *pgd;
unsigned long next;
- unsigned long end = addr + size;
+ unsigned long end = addr + PAGE_ALIGN(size);
struct mm_struct *mm = vma->vm_mm;
int err;
@@ -1264,7 +1235,7 @@ static int do_wp_page(struct mm_struct *mm, struct vm_area_struct * vma,
}
old_page = pfn_to_page(pfn);
- if (!TestSetPageLocked(old_page)) {
+ if (PageAnon(old_page) && !TestSetPageLocked(old_page)) {
int reuse = can_share_swap_page(old_page);
unlock_page(old_page);
if (reuse) {
@@ -1483,7 +1454,7 @@ restart:
* unmap_mapping_range - unmap the portion of all mmaps
* in the specified address_space corresponding to the specified
* page range in the underlying file.
- * @address_space: the address space containing mmaps to be unmapped.
+ * @mapping: the address space containing mmaps to be unmapped.
* @holebegin: byte in first page to unmap, relative to the start of
* the underlying file. This will be rounded down to a PAGE_SIZE
* boundary. Note that this is different from vmtruncate(), which
@@ -1711,10 +1682,6 @@ static int do_swap_page(struct mm_struct * mm,
}
/* The page isn't present yet, go ahead with the fault. */
-
- swap_free(entry);
- if (vm_swap_full())
- remove_exclusive_swap_page(page);
inc_mm_counter(mm, rss);
pte = mk_pte(page, vma->vm_page_prot);
@@ -1722,12 +1689,16 @@ static int do_swap_page(struct mm_struct * mm,
pte = maybe_mkwrite(pte_mkdirty(pte), vma);
write_access = 0;
}
- unlock_page(page);
flush_icache_page(vma, page);
set_pte_at(mm, address, page_table, pte);
page_add_anon_rmap(page, vma, address);
+ swap_free(entry);
+ if (vm_swap_full())
+ remove_exclusive_swap_page(page);
+ unlock_page(page);
+
if (write_access) {
if (do_wp_page(mm, vma, address,
page_table, pmd, pte) == VM_FAULT_OOM)
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-01-03 11:12:37 +0000