X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=mm%2Fmemory.c;h=fc1987dfd8cc7f62fa911fd905f743cb3ec53ec3;hb=8dfb790b15e779232d5d4e3f0102af2bea21ca55;hp=f1a68049edfff60805e2c1019c4d950bfb3e5ed6;hpb=3477d168ba61c5b0ca42d3d4642f3463609a5417;p=cascardo%2Flinux.git

diff --git a/mm/memory.c b/mm/memory.c
index f1a68049edff..fc1987dfd8cc 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1649,10 +1649,14 @@ EXPORT_SYMBOL(vm_insert_pfn_prot);
 int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 			pfn_t pfn)
 {
+	pgprot_t pgprot = vma->vm_page_prot;
+
 	BUG_ON(!(vma->vm_flags & VM_MIXEDMAP));
 
 	if (addr < vma->vm_start || addr >= vma->vm_end)
 		return -EFAULT;
+	if (track_pfn_insert(vma, &pgprot, pfn))
+		return -EINVAL;
 
 	/*
 	 * If we don't have pte special, then we have to use the pfn_valid()
@@ -1670,9 +1674,9 @@ int vm_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
 		 * result in pfn_t_has_page() == false.
 		 */
 		page = pfn_to_page(pfn_t_to_pfn(pfn));
-		return insert_page(vma, addr, page, vma->vm_page_prot);
+		return insert_page(vma, addr, page, pgprot);
 	}
-	return insert_pfn(vma, addr, pfn, vma->vm_page_prot);
+	return insert_pfn(vma, addr, pfn, pgprot);
 }
 EXPORT_SYMBOL(vm_insert_mixed);
 
@@ -3658,6 +3662,19 @@ int handle_mm_fault(struct vm_area_struct *vma, unsigned long address,
                         mem_cgroup_oom_synchronize(false);
 	}
 
+	/*
+	 * This mm has been already reaped by the oom reaper and so the
+	 * refault cannot be trusted in general. Anonymous refaults would
+	 * lose data and give a zero page instead e.g. This is especially
+	 * problem for use_mm() because regular tasks will just die and
+	 * the corrupted data will not be visible anywhere while kthread
+	 * will outlive the oom victim and potentially propagate the date
+	 * further.
+	 */
+	if (unlikely((current->flags & PF_KTHREAD) && !(ret & VM_FAULT_ERROR)
+				&& test_bit(MMF_UNSTABLE, &vma->vm_mm->flags)))
+		ret = VM_FAULT_SIGBUS;
+
 	return ret;
 }
 EXPORT_SYMBOL_GPL(handle_mm_fault);