Merge branch 'akpm' (patches from Andrew)

Merge misc fixes from Andrew Morton:
 "18 fixes"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
  mm, swap: use page-cluster as max window of VMA based swap readahead
  mm: page_vma_mapped: ensure pmd is loaded with READ_ONCE outside of lock
  kmemleak: clear stale pointers from task stacks
  fs/binfmt_misc.c: node could be NULL when evicting inode
  fs/mpage.c: fix mpage_writepage() for pages with buffers
  linux/kernel.h: add/correct kernel-doc notation
  tty: fall back to N_NULL if switching to N_TTY fails during hangup
  Revert "vmalloc: back off when the current task is killed"
  mm/cma.c: take __GFP_NOWARN into account in cma_alloc()
  scripts/kallsyms.c: ignore symbol type 'n'
  userfaultfd: selftest: exercise -EEXIST only in background transfer
  mm: only display online cpus of the numa node
  mm: remove unnecessary WARN_ONCE in page_vma_mapped_walk().
  mm/mempolicy: fix NUMA_INTERLEAVE_HIT counter
  include/linux/of.h: provide of_n_{addr,size}_cells wrappers for !CONFIG_OF
  mm/madvise.c: add description for MADV_WIPEONFORK and MADV_KEEPONFORK
  lib/Kconfig.debug: kernel hacking menu: runtime testing: keep tests together
  mm/migrate: fix indexing bug (off by one) and avoid out of bound access

1 files changed, 20 insertions, 5 deletions

diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index a2c53a3d223d..de2f9ec8a87f 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -397,7 +397,7 @@ static void retry_copy_page(int ufd, struct uffdio_copy *uffdio_copy,
 	}
 }
 
-static int copy_page(int ufd, unsigned long offset)
+static int __copy_page(int ufd, unsigned long offset, bool retry)
 {
 	struct uffdio_copy uffdio_copy;
 
@@ -418,7 +418,7 @@ static int copy_page(int ufd, unsigned long offset)
 		fprintf(stderr, "UFFDIO_COPY unexpected copy %Ld\n",
 			uffdio_copy.copy), exit(1);
 	} else {
-		if (test_uffdio_copy_eexist) {
+		if (test_uffdio_copy_eexist && retry) {
 			test_uffdio_copy_eexist = false;
 			retry_copy_page(ufd, &uffdio_copy, offset);
 		}
@@ -427,6 +427,16 @@ static int copy_page(int ufd, unsigned long offset)
 	return 0;
 }
 
+static int copy_page_retry(int ufd, unsigned long offset)
+{
+	return __copy_page(ufd, offset, true);
+}
+
+static int copy_page(int ufd, unsigned long offset)
+{
+	return __copy_page(ufd, offset, false);
+}
+
 static void *uffd_poll_thread(void *arg)
 {
 	unsigned long cpu = (unsigned long) arg;
@@ -544,7 +554,7 @@ static void *background_thread(void *arg)
 	for (page_nr = cpu * nr_pages_per_cpu;
 	     page_nr < (cpu+1) * nr_pages_per_cpu;
 	     page_nr++)
-		copy_page(uffd, page_nr * page_size);
+		copy_page_retry(uffd, page_nr * page_size);
 
 	return NULL;
 }
@@ -779,7 +789,7 @@ static void retry_uffdio_zeropage(int ufd,
 	}
 }
 
-static int uffdio_zeropage(int ufd, unsigned long offset)
+static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry)
 {
 	struct uffdio_zeropage uffdio_zeropage;
 	int ret;
@@ -814,7 +824,7 @@ static int uffdio_zeropage(int ufd, unsigned long offset)
 			fprintf(stderr, "UFFDIO_ZEROPAGE unexpected %Ld\n",
 				uffdio_zeropage.zeropage), exit(1);
 		} else {
-			if (test_uffdio_zeropage_eexist) {
+			if (test_uffdio_zeropage_eexist && retry) {
 				test_uffdio_zeropage_eexist = false;
 				retry_uffdio_zeropage(ufd, &uffdio_zeropage,
 						      offset);
@@ -830,6 +840,11 @@ static int uffdio_zeropage(int ufd, unsigned long offset)
 	return 0;
 }
 
+static int uffdio_zeropage(int ufd, unsigned long offset)
+{
+	return __uffdio_zeropage(ufd, offset, false);
+}
+
 /* exercise UFFDIO_ZEROPAGE */
 static int userfaultfd_zeropage_test(void)
 {