static const struct mm_walk_ops break_ksm_ops = {
.pmd_entry = break_ksm_pmd_entry,
+ .walk_lock = PGWALK_RDLOCK,
+};
+
+static const struct mm_walk_ops break_ksm_lock_vma_ops = {
+ .pmd_entry = break_ksm_pmd_entry,
+ .walk_lock = PGWALK_WRLOCK,
};
/*
* of the process that owns 'vma'. We also do not want to enforce
* protection keys here anyway.
*/
-static int break_ksm(struct vm_area_struct *vma, unsigned long addr)
+static int break_ksm(struct vm_area_struct *vma, unsigned long addr, bool lock_vma)
{
vm_fault_t ret = 0;
+ const struct mm_walk_ops *ops = lock_vma ?
+ &break_ksm_lock_vma_ops : &break_ksm_ops;
do {
int ksm_page;
cond_resched();
- ksm_page = walk_page_range_vma(vma, addr, addr + 1,
- &break_ksm_ops, NULL);
+ ksm_page = walk_page_range_vma(vma, addr, addr + 1, ops, NULL);
if (WARN_ON_ONCE(ksm_page < 0))
return ksm_page;
if (!ksm_page)
mmap_read_lock(mm);
vma = find_mergeable_vma(mm, addr);
if (vma)
- break_ksm(vma, addr);
+ break_ksm(vma, addr, false);
mmap_read_unlock(mm);
}
* in cmp_and_merge_page on one of the rmap_items we would be removing.
*/
static int unmerge_ksm_pages(struct vm_area_struct *vma,
- unsigned long start, unsigned long end)
+ unsigned long start, unsigned long end, bool lock_vma)
{
unsigned long addr;
int err = 0;
if (signal_pending(current))
err = -ERESTARTSYS;
else
- err = break_ksm(vma, addr);
+ err = break_ksm(vma, addr, lock_vma);
}
return err;
}
if (!(vma->vm_flags & VM_MERGEABLE) || !vma->anon_vma)
continue;
err = unmerge_ksm_pages(vma,
- vma->vm_start, vma->vm_end);
+ vma->vm_start, vma->vm_end, false);
if (err)
goto error;
}
return 0;
if (vma->anon_vma) {
- err = unmerge_ksm_pages(vma, vma->vm_start, vma->vm_end);
+ err = unmerge_ksm_pages(vma, vma->vm_start, vma->vm_end, true);
if (err)
return err;
}
return 0; /* just ignore the advice */
if (vma->anon_vma) {
- err = unmerge_ksm_pages(vma, start, end);
+ err = unmerge_ksm_pages(vma, start, end, true);
if (err)
return err;
}
anon_vma->root == vma->anon_vma->root) {
return page; /* still no need to copy it */
}
+ if (PageHWPoison(page))
+ return ERR_PTR(-EHWPOISON);
if (!PageUptodate(page))
return page; /* let do_swap_page report the error */