3 files changed, 15 insertions, 9 deletions

diff --git a/mm/internal.h b/mm/internal.h
index 1981bc9454f3..478223b73a2a 100644
--- a/mm/internal.h
+++ b/mm/internal.h
@@ -276,6 +276,7 @@ static inline void mminit_validate_memmodel_limits(unsigned long *start_pfn,
 #define GUP_FLAGS_WRITE                  0x1
 #define GUP_FLAGS_FORCE                  0x2
 #define GUP_FLAGS_IGNORE_VMA_PERMISSIONS 0x4
+#define GUP_FLAGS_IGNORE_SIGKILL         0x8
 
 int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                      unsigned long start, int len, int flags,
diff --git a/mm/memory.c b/mm/memory.c
index db68af8e0bc4..3f8fa06b963b 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1210,6 +1210,7 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
         int write = !!(flags & GUP_FLAGS_WRITE);
         int force = !!(flags & GUP_FLAGS_FORCE);
         int ignore = !!(flags & GUP_FLAGS_IGNORE_VMA_PERMISSIONS);
+        int ignore_sigkill = !!(flags & GUP_FLAGS_IGNORE_SIGKILL);
 
         if (len <= 0)
                 return 0;
@@ -1288,12 +1289,15 @@ int __get_user_pages(struct task_struct *tsk, struct mm_struct *mm,
                         struct page *page;
 
                         /*
-                         * If tsk is ooming, cut off its access to large memory
-                         * allocations. It has a pending SIGKILL, but it can't
-                         * be processed until returning to user space.
+                         * If we have a pending SIGKILL, don't keep faulting
+                         * pages and potentially allocating memory, unless
+                         * current is handling munlock--e.g., on exit. In
+                         * that case, we are not allocating memory.  Rather,
+                         * we're only unlocking already resident/mapped pages.
                          */
-                        if (unlikely(test_tsk_thread_flag(tsk, TIF_MEMDIE)))
-                                return i ? i : -ENOMEM;
+                        if (unlikely(!ignore_sigkill &&
+                                        fatal_signal_pending(current)))
+                                return i ? i : -ERESTARTSYS;
 
                         if (write)
                                 foll_flags |= FOLL_WRITE;
diff --git a/mm/mlock.c b/mm/mlock.c
index 3035a56e7616..e125156c664e 100644
--- a/mm/mlock.c
+++ b/mm/mlock.c
@@ -173,12 +173,13 @@ static long __mlock_vma_pages_range(struct vm_area_struct *vma,
                   (atomic_read(&mm->mm_users) != 0));
 
         /*
-         * mlock:   don't page populate if page has PROT_NONE permission.
-         * munlock: the pages always do munlock althrough
-         *          its has PROT_NONE permission.
+         * mlock:   don't page populate if vma has PROT_NONE permission.
+         * munlock: always do munlock although the vma has PROT_NONE
+         *          permission, or SIGKILL is pending.
          */
         if (!mlock)
-                gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS;
+                gup_flags |= GUP_FLAGS_IGNORE_VMA_PERMISSIONS |
+                             GUP_FLAGS_IGNORE_SIGKILL;
 
         if (vma->vm_flags & VM_WRITE)
                 gup_flags |= GUP_FLAGS_WRITE;