[PATCH v8 13/24] mm: Introduce __lru_cache_add_active_or_unevictable

From: Laurent Dufour
Date: Fri Feb 16 2018 - 10:26:46 EST


The speculative page fault handler which is run without holding the
mmap_sem is calling lru_cache_add_active_or_unevictable() but the vm_flags
is not guaranteed to remain constant.
Introducing __lru_cache_add_active_or_unevictable() which has the vma flags
value parameter instead of the vma pointer.

Signed-off-by: Laurent Dufour <ldufour@xxxxxxxxxxxxxxxxxx>
---
include/linux/swap.h | 10 ++++++++--
mm/memory.c | 8 ++++----
mm/swap.c | 6 +++---
3 files changed, 15 insertions(+), 9 deletions(-)

diff --git a/include/linux/swap.h b/include/linux/swap.h
index a1a3f4ed94ce..99377b66ea93 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -337,8 +337,14 @@ extern void deactivate_file_page(struct page *page);
extern void mark_page_lazyfree(struct page *page);
extern void swap_setup(void);

-extern void lru_cache_add_active_or_unevictable(struct page *page,
- struct vm_area_struct *vma);
+extern void __lru_cache_add_active_or_unevictable(struct page *page,
+ unsigned long vma_flags);
+
+static inline void lru_cache_add_active_or_unevictable(struct page *page,
+ struct vm_area_struct *vma)
+{
+ return __lru_cache_add_active_or_unevictable(page, vma->vm_flags);
+}

/* linux/mm/vmscan.c */
extern unsigned long zone_reclaimable_pages(struct zone *zone);
diff --git a/mm/memory.c b/mm/memory.c
index bd5de1aa3f7a..bc14973b4eba 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -2560,7 +2560,7 @@ static int wp_page_copy(struct vm_fault *vmf)
ptep_clear_flush_notify(vma, vmf->address, vmf->pte);
page_add_new_anon_rmap(new_page, vma, vmf->address, false);
mem_cgroup_commit_charge(new_page, memcg, false, false);
- lru_cache_add_active_or_unevictable(new_page, vma);
+ __lru_cache_add_active_or_unevictable(new_page, vmf->vma_flags);
/*
* We call the notify macro here because, when using secondary
* mmu page tables (such as kvm shadow page tables), we want the
@@ -3106,7 +3106,7 @@ int do_swap_page(struct vm_fault *vmf)
if (unlikely(page != swapcache && swapcache)) {
page_add_new_anon_rmap(page, vma, vmf->address, false);
mem_cgroup_commit_charge(page, memcg, false, false);
- lru_cache_add_active_or_unevictable(page, vma);
+ __lru_cache_add_active_or_unevictable(page, vmf->vma_flags);
} else {
do_page_add_anon_rmap(page, vma, vmf->address, exclusive);
mem_cgroup_commit_charge(page, memcg, true, false);
@@ -3257,7 +3257,7 @@ static int do_anonymous_page(struct vm_fault *vmf)
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
page_add_new_anon_rmap(page, vma, vmf->address, false);
mem_cgroup_commit_charge(page, memcg, false, false);
- lru_cache_add_active_or_unevictable(page, vma);
+ __lru_cache_add_active_or_unevictable(page, vmf->vma_flags);
setpte:
set_pte_at(vma->vm_mm, vmf->address, vmf->pte, entry);

@@ -3509,7 +3509,7 @@ int alloc_set_pte(struct vm_fault *vmf, struct mem_cgroup *memcg,
inc_mm_counter_fast(vma->vm_mm, MM_ANONPAGES);
page_add_new_anon_rmap(page, vma, vmf->address, false);
mem_cgroup_commit_charge(page, memcg, false, false);
- lru_cache_add_active_or_unevictable(page, vma);
+ __lru_cache_add_active_or_unevictable(page, vmf->vma_flags);
} else {
inc_mm_counter_fast(vma->vm_mm, mm_counter_file(page));
page_add_file_rmap(page, false);
diff --git a/mm/swap.c b/mm/swap.c
index 2d337710218f..85fc6e78ca99 100644
--- a/mm/swap.c
+++ b/mm/swap.c
@@ -455,12 +455,12 @@ void lru_cache_add(struct page *page)
* directly back onto it's zone's unevictable list, it does NOT use a
* per cpu pagevec.
*/
-void lru_cache_add_active_or_unevictable(struct page *page,
- struct vm_area_struct *vma)
+void __lru_cache_add_active_or_unevictable(struct page *page,
+ unsigned long vma_flags)
{
VM_BUG_ON_PAGE(PageLRU(page), page);

- if (likely((vma->vm_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
+ if (likely((vma_flags & (VM_LOCKED | VM_SPECIAL)) != VM_LOCKED))
SetPageActive(page);
else if (!TestSetPageMlocked(page)) {
/*
--
2.7.4