Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:

 - most of the rest of MM

 - KASAN updates

 - lib/ updates

 - checkpatch updates

 - some binfmt_elf changes

 - various misc bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (115 commits)
  kernel/exit.c: avoid undefined behaviour when calling wait4()
  kernel/signal.c: avoid undefined behaviour in kill_something_info
  binfmt_elf: safely increment argv pointers
  s390: reduce ELF_ET_DYN_BASE
  powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm64: move ELF_ET_DYN_BASE to 4GB / 4MB
  arm: move ELF_ET_DYN_BASE to 4MB
  binfmt_elf: use ELF_ET_DYN_BASE only for PIE
  fs, epoll: short circuit fetching events if thread has been killed
  checkpatch: improve multi-line alignment test
  checkpatch: improve macro reuse test
  checkpatch: change format of --color argument to --color[=WHEN]
  checkpatch: silence perl 5.26.0 unescaped left brace warnings
  checkpatch: improve tests for multiple line function definitions
  checkpatch: remove false warning for commit reference
  checkpatch: fix stepping through statements with $stat and ctx_statement_block
  checkpatch: [HLP]LIST_HEAD is also declaration
  checkpatch: warn when a MAINTAINERS entry isn't [A-Z]:\t
  checkpatch: improve the unnecessary OOM message test
  lib/bsearch.c: micro-optimize pivot position calculation
  ...

1 files changed, 24 insertions, 22 deletions

diff --git a/mm/madvise.c b/mm/madvise.c
index 25b78ee4fc2c..9976852f1e1c 100644
--- a/mm/madvise.c
+++ b/mm/madvise.c
@@ -205,7 +205,7 @@ static int swapin_walk_pmd_entry(pmd_t *pmd, unsigned long start,
 			continue;
 
 		page = read_swap_cache_async(entry, GFP_HIGHUSER_MOVABLE,
-								vma, index);
+							vma, index, false);
 		if (page)
 			put_page(page);
 	}
@@ -246,7 +246,7 @@ static void force_shm_swapin_readahead(struct vm_area_struct *vma,
 		}
 		swap = radix_to_swp_entry(page);
 		page = read_swap_cache_async(swap, GFP_HIGHUSER_MOVABLE,
-								NULL, 0);
+							NULL, 0, false);
 		if (page)
 			put_page(page);
 	}
@@ -451,9 +451,6 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
 	struct mm_struct *mm = vma->vm_mm;
 	struct mmu_gather tlb;
 
-	if (vma->vm_flags & (VM_LOCKED|VM_HUGETLB|VM_PFNMAP))
-		return -EINVAL;
-
 	/* MADV_FREE works for only anon vma at the moment */
 	if (!vma_is_anonymous(vma))
 		return -EINVAL;
@@ -477,14 +474,6 @@ static int madvise_free_single_vma(struct vm_area_struct *vma,
 	return 0;
 }
 
-static long madvise_free(struct vm_area_struct *vma,
-			     struct vm_area_struct **prev,
-			     unsigned long start, unsigned long end)
-{
-	*prev = vma;
-	return madvise_free_single_vma(vma, start, end);
-}
-
 /*
  * Application no longer needs these pages.  If the pages are dirty,
  * it's OK to just throw them away.  The app will be more careful about
@@ -504,9 +493,17 @@ static long madvise_free(struct vm_area_struct *vma,
  * An interface that causes the system to free clean pages and flush
  * dirty pages is already available as msync(MS_INVALIDATE).
  */
-static long madvise_dontneed(struct vm_area_struct *vma,
-			     struct vm_area_struct **prev,
-			     unsigned long start, unsigned long end)
+static long madvise_dontneed_single_vma(struct vm_area_struct *vma,
+					unsigned long start, unsigned long end)
+{
+	zap_page_range(vma, start, end - start);
+	return 0;
+}
+
+static long madvise_dontneed_free(struct vm_area_struct *vma,
+				  struct vm_area_struct **prev,
+				  unsigned long start, unsigned long end,
+				  int behavior)
 {
 	*prev = vma;
 	if (!can_madv_dontneed_vma(vma))
@@ -526,7 +523,8 @@ static long madvise_dontneed(struct vm_area_struct *vma,
 			 * is also < vma->vm_end. If start <
 			 * vma->vm_start it means an hole materialized
 			 * in the user address space within the
-			 * virtual range passed to MADV_DONTNEED.
+			 * virtual range passed to MADV_DONTNEED
+			 * or MADV_FREE.
 			 */
 			return -ENOMEM;
 		}
@@ -537,7 +535,7 @@ static long madvise_dontneed(struct vm_area_struct *vma,
 			 * Don't fail if end > vma->vm_end. If the old
 			 * vma was splitted while the mmap_sem was
 			 * released the effect of the concurrent
-			 * operation may not cause MADV_DONTNEED to
+			 * operation may not cause madvise() to
 			 * have an undefined result. There may be an
 			 * adjacent next vma that we'll walk
 			 * next. userfaultfd_remove() will generate an
@@ -549,8 +547,13 @@ static long madvise_dontneed(struct vm_area_struct *vma,
 		}
 		VM_WARN_ON(start >= end);
 	}
-	zap_page_range(vma, start, end - start);
-	return 0;
+
+	if (behavior == MADV_DONTNEED)
+		return madvise_dontneed_single_vma(vma, start, end);
+	else if (behavior == MADV_FREE)
+		return madvise_free_single_vma(vma, start, end);
+	else
+		return -EINVAL;
 }
 
 /*
@@ -656,9 +659,8 @@ madvise_vma(struct vm_area_struct *vma, struct vm_area_struct **prev,
 	case MADV_WILLNEED:
 		return madvise_willneed(vma, prev, start, end);
 	case MADV_FREE:
-		return madvise_free(vma, prev, start, end);
 	case MADV_DONTNEED:
-		return madvise_dontneed(vma, prev, start, end);
+		return madvise_dontneed_free(vma, prev, start, end, behavior);
 	default:
 		return madvise_behavior(vma, prev, start, end, behavior);
 	}