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, 21 insertions, 2 deletions

diff --git a/mm/page_io.c b/mm/page_io.c
index 2da71e627812..b6c4ac388209 100644
--- a/mm/page_io.c
+++ b/mm/page_io.c
@@ -117,6 +117,7 @@ static void swap_slot_free_notify(struct page *page)
 static void end_swap_bio_read(struct bio *bio)
 {
 	struct page *page = bio->bi_io_vec[0].bv_page;
+	struct task_struct *waiter = bio->bi_private;
 
 	if (bio->bi_status) {
 		SetPageError(page);
@@ -132,7 +133,9 @@ static void end_swap_bio_read(struct bio *bio)
 	swap_slot_free_notify(page);
 out:
 	unlock_page(page);
+	WRITE_ONCE(bio->bi_private, NULL);
 	bio_put(bio);
+	wake_up_process(waiter);
 }
 
 int generic_swapfile_activate(struct swap_info_struct *sis,
@@ -329,11 +332,13 @@ out:
 	return ret;
 }
 
-int swap_readpage(struct page *page)
+int swap_readpage(struct page *page, bool do_poll)
 {
 	struct bio *bio;
 	int ret = 0;
 	struct swap_info_struct *sis = page_swap_info(page);
+	blk_qc_t qc;
+	struct block_device *bdev;
 
 	VM_BUG_ON_PAGE(!PageSwapCache(page), page);
 	VM_BUG_ON_PAGE(!PageLocked(page), page);
@@ -372,9 +377,23 @@ int swap_readpage(struct page *page)
 		ret = -ENOMEM;
 		goto out;
 	}
+	bdev = bio->bi_bdev;
+	bio->bi_private = current;
 	bio_set_op_attrs(bio, REQ_OP_READ, 0);
 	count_vm_event(PSWPIN);
-	submit_bio(bio);
+	bio_get(bio);
+	qc = submit_bio(bio);
+	while (do_poll) {
+		set_current_state(TASK_UNINTERRUPTIBLE);
+		if (!READ_ONCE(bio->bi_private))
+			break;
+
+		if (!blk_mq_poll(bdev_get_queue(bdev), qc))
+			break;
+	}
+	__set_current_state(TASK_RUNNING);
+	bio_put(bio);
+
 out:
 	return ret;
 }