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Diffstat (limited to 'mm/memory.c')
-rw-r--r--mm/memory.c35
1 files changed, 29 insertions, 6 deletions
diff --git a/mm/memory.c b/mm/memory.c
index a8ca04faaea..67f0ab9077d 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -51,6 +51,7 @@
#include <linux/init.h>
#include <linux/writeback.h>
#include <linux/memcontrol.h>
+#include <linux/mmu_notifier.h>
#include <asm/pgalloc.h>
#include <asm/uaccess.h>
@@ -652,6 +653,7 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
unsigned long next;
unsigned long addr = vma->vm_start;
unsigned long end = vma->vm_end;
+ int ret;
/*
* Don't copy ptes where a page fault will fill them correctly.
@@ -667,17 +669,33 @@ int copy_page_range(struct mm_struct *dst_mm, struct mm_struct *src_mm,
if (is_vm_hugetlb_page(vma))
return copy_hugetlb_page_range(dst_mm, src_mm, vma);
+ /*
+ * We need to invalidate the secondary MMU mappings only when
+ * there could be a permission downgrade on the ptes of the
+ * parent mm. And a permission downgrade will only happen if
+ * is_cow_mapping() returns true.
+ */
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_start(src_mm, addr, end);
+
+ ret = 0;
dst_pgd = pgd_offset(dst_mm, addr);
src_pgd = pgd_offset(src_mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(src_pgd))
continue;
- if (copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
- vma, addr, next))
- return -ENOMEM;
+ if (unlikely(copy_pud_range(dst_mm, src_mm, dst_pgd, src_pgd,
+ vma, addr, next))) {
+ ret = -ENOMEM;
+ break;
+ }
} while (dst_pgd++, src_pgd++, addr = next, addr != end);
- return 0;
+
+ if (is_cow_mapping(vma->vm_flags))
+ mmu_notifier_invalidate_range_end(src_mm,
+ vma->vm_start, end);
+ return ret;
}
static unsigned long zap_pte_range(struct mmu_gather *tlb,
@@ -881,7 +899,9 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
unsigned long start = start_addr;
spinlock_t *i_mmap_lock = details? details->i_mmap_lock: NULL;
int fullmm = (*tlbp)->fullmm;
+ struct mm_struct *mm = vma->vm_mm;
+ mmu_notifier_invalidate_range_start(mm, start_addr, end_addr);
for ( ; vma && vma->vm_start < end_addr; vma = vma->vm_next) {
unsigned long end;
@@ -946,6 +966,7 @@ unsigned long unmap_vmas(struct mmu_gather **tlbp,
}
}
out:
+ mmu_notifier_invalidate_range_end(mm, start_addr, end_addr);
return start; /* which is now the end (or restart) address */
}
@@ -1616,10 +1637,11 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
{
pgd_t *pgd;
unsigned long next;
- unsigned long end = addr + size;
+ unsigned long start = addr, end = addr + size;
int err;
BUG_ON(addr >= end);
+ mmu_notifier_invalidate_range_start(mm, start, end);
pgd = pgd_offset(mm, addr);
do {
next = pgd_addr_end(addr, end);
@@ -1627,6 +1649,7 @@ int apply_to_page_range(struct mm_struct *mm, unsigned long addr,
if (err)
break;
} while (pgd++, addr = next, addr != end);
+ mmu_notifier_invalidate_range_end(mm, start, end);
return err;
}
EXPORT_SYMBOL_GPL(apply_to_page_range);
@@ -1839,7 +1862,7 @@ gotten:
* seen in the presence of one thread doing SMC and another
* thread doing COW.
*/
- ptep_clear_flush(vma, address, page_table);
+ ptep_clear_flush_notify(vma, address, page_table);
set_pte_at(mm, address, page_table, entry);
update_mmu_cache(vma, address, entry);
lru_cache_add_active(new_page);