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-rw-r--r--mm/internal.h53
-rw-r--r--mm/page_vma_mapped.c16
-rw-r--r--mm/rmap.c16
3 files changed, 53 insertions, 32 deletions
diff --git a/mm/internal.h b/mm/internal.h
index 2f1182948aa6..e8fdb531f887 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -384,27 +384,52 @@ static inline void mlock_migrate_page(struct page *newpage, struct page *page)
extern pmd_t maybe_pmd_mkwrite(pmd_t pmd, struct vm_area_struct *vma);
/*
- * At what user virtual address is page expected in @vma?
+ * At what user virtual address is page expected in vma?
+ * Returns -EFAULT if all of the page is outside the range of vma.
+ * If page is a compound head, the entire compound page is considered.
*/
static inline unsigned long
-__vma_address(struct page *page, struct vm_area_struct *vma)
+vma_address(struct page *page, struct vm_area_struct *vma)
{
- pgoff_t pgoff = page_to_pgoff(page);
- return vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ pgoff_t pgoff;
+ unsigned long address;
+
+ VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */
+ pgoff = page_to_pgoff(page);
+ if (pgoff >= vma->vm_pgoff) {
+ address = vma->vm_start +
+ ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ /* Check for address beyond vma (or wrapped through 0?) */
+ if (address < vma->vm_start || address >= vma->vm_end)
+ address = -EFAULT;
+ } else if (PageHead(page) &&
+ pgoff + compound_nr(page) - 1 >= vma->vm_pgoff) {
+ /* Test above avoids possibility of wrap to 0 on 32-bit */
+ address = vma->vm_start;
+ } else {
+ address = -EFAULT;
+ }
+ return address;
}
+/*
+ * Then at what user virtual address will none of the page be found in vma?
+ * Assumes that vma_address() already returned a good starting address.
+ * If page is a compound head, the entire compound page is considered.
+ */
static inline unsigned long
-vma_address(struct page *page, struct vm_area_struct *vma)
+vma_address_end(struct page *page, struct vm_area_struct *vma)
{
- unsigned long start, end;
-
- start = __vma_address(page, vma);
- end = start + thp_size(page) - PAGE_SIZE;
-
- /* page should be within @vma mapping range */
- VM_BUG_ON_VMA(end < vma->vm_start || start >= vma->vm_end, vma);
-
- return max(start, vma->vm_start);
+ pgoff_t pgoff;
+ unsigned long address;
+
+ VM_BUG_ON_PAGE(PageKsm(page), page); /* KSM page->index unusable */
+ pgoff = page_to_pgoff(page) + compound_nr(page);
+ address = vma->vm_start + ((pgoff - vma->vm_pgoff) << PAGE_SHIFT);
+ /* Check for address beyond vma (or wrapped through 0?) */
+ if (address < vma->vm_start || address > vma->vm_end)
+ address = vma->vm_end;
+ return address;
}
static inline struct file *maybe_unlock_mmap_for_io(struct vm_fault *vmf,
diff --git a/mm/page_vma_mapped.c b/mm/page_vma_mapped.c
index 5b559967410e..e37bd43904af 100644
--- a/mm/page_vma_mapped.c
+++ b/mm/page_vma_mapped.c
@@ -228,18 +228,18 @@ restart:
if (!map_pte(pvmw))
goto next_pte;
while (1) {
+ unsigned long end;
+
if (check_pte(pvmw))
return true;
next_pte:
/* Seek to next pte only makes sense for THP */
if (!PageTransHuge(pvmw->page) || PageHuge(pvmw->page))
return not_found(pvmw);
+ end = vma_address_end(pvmw->page, pvmw->vma);
do {
pvmw->address += PAGE_SIZE;
- if (pvmw->address >= pvmw->vma->vm_end ||
- pvmw->address >=
- __vma_address(pvmw->page, pvmw->vma) +
- thp_size(pvmw->page))
+ if (pvmw->address >= end)
return not_found(pvmw);
/* Did we cross page table boundary? */
if (pvmw->address % PMD_SIZE == 0) {
@@ -277,14 +277,10 @@ int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma)
.vma = vma,
.flags = PVMW_SYNC,
};
- unsigned long start, end;
-
- start = __vma_address(page, vma);
- end = start + thp_size(page) - PAGE_SIZE;
- if (unlikely(end < vma->vm_start || start >= vma->vm_end))
+ pvmw.address = vma_address(page, vma);
+ if (pvmw.address == -EFAULT)
return 0;
- pvmw.address = max(start, vma->vm_start);
if (!page_vma_mapped_walk(&pvmw))
return 0;
page_vma_mapped_walk_done(&pvmw);
diff --git a/mm/rmap.c b/mm/rmap.c
index 07811b4ae793..144de54efc1c 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -707,7 +707,6 @@ static bool should_defer_flush(struct mm_struct *mm, enum ttu_flags flags)
*/
unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
{
- unsigned long address;
if (PageAnon(page)) {
struct anon_vma *page__anon_vma = page_anon_vma(page);
/*
@@ -722,10 +721,8 @@ unsigned long page_address_in_vma(struct page *page, struct vm_area_struct *vma)
return -EFAULT;
} else
return -EFAULT;
- address = __vma_address(page, vma);
- if (unlikely(address < vma->vm_start || address >= vma->vm_end))
- return -EFAULT;
- return address;
+
+ return vma_address(page, vma);
}
pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address)
@@ -919,7 +916,7 @@ static bool page_mkclean_one(struct page *page, struct vm_area_struct *vma,
*/
mmu_notifier_range_init(&range, MMU_NOTIFY_PROTECTION_PAGE,
0, vma, vma->vm_mm, address,
- min(vma->vm_end, address + page_size(page)));
+ vma_address_end(page, vma));
mmu_notifier_invalidate_range_start(&range);
while (page_vma_mapped_walk(&pvmw)) {
@@ -1435,9 +1432,10 @@ static bool try_to_unmap_one(struct page *page, struct vm_area_struct *vma,
* Note that the page can not be free in this function as call of
* try_to_unmap() must hold a reference on the page.
*/
+ range.end = PageKsm(page) ?
+ address + PAGE_SIZE : vma_address_end(page, vma);
mmu_notifier_range_init(&range, MMU_NOTIFY_CLEAR, 0, vma, vma->vm_mm,
- address,
- min(vma->vm_end, address + page_size(page)));
+ address, range.end);
if (PageHuge(page)) {
/*
* If sharing is possible, start and end will be adjusted
@@ -1889,6 +1887,7 @@ static void rmap_walk_anon(struct page *page, struct rmap_walk_control *rwc,
struct vm_area_struct *vma = avc->vma;
unsigned long address = vma_address(page, vma);
+ VM_BUG_ON_VMA(address == -EFAULT, vma);
cond_resched();
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
@@ -1943,6 +1942,7 @@ static void rmap_walk_file(struct page *page, struct rmap_walk_control *rwc,
pgoff_start, pgoff_end) {
unsigned long address = vma_address(page, vma);
+ VM_BUG_ON_VMA(address == -EFAULT, vma);
cond_resched();
if (rwc->invalid_vma && rwc->invalid_vma(vma, rwc->arg))
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-17 10:48:18 +0300