Merge remote-tracking branch 'torvalds/master' into perf/core

To sync with libbpf, etc.

Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

1 files changed, 19 insertions, 6 deletions

diff --git a/mm/mremap.c b/mm/mremap.c
index fe587c5d6591..930f65c315c0 100644
--- a/mm/mremap.c
+++ b/mm/mremap.c
@@ -1027,16 +1027,29 @@ SYSCALL_DEFINE5(mremap, unsigned long, addr, unsigned long, old_len,
 			}
 
 			/*
-			 * Function vma_merge() is called on the extension we are adding to
-			 * the already existing vma, vma_merge() will merge this extension with
-			 * the already existing vma (expand operation itself) and possibly also
-			 * with the next vma if it becomes adjacent to the expanded vma and
-			 * otherwise compatible.
+			 * Function vma_merge() is called on the extension we
+			 * are adding to the already existing vma, vma_merge()
+			 * will merge this extension with the already existing
+			 * vma (expand operation itself) and possibly also with
+			 * the next vma if it becomes adjacent to the expanded
+			 * vma and  otherwise compatible.
+			 *
+			 * However, vma_merge() can currently fail due to
+			 * is_mergeable_vma() check for vm_ops->close (see the
+			 * comment there). Yet this should not prevent vma
+			 * expanding, so perform a simple expand for such vma.
+			 * Ideally the check for close op should be only done
+			 * when a vma would be actually removed due to a merge.
 			 */
-			vma = vma_merge(mm, vma, extension_start, extension_end,
+			if (!vma->vm_ops || !vma->vm_ops->close) {
+				vma = vma_merge(mm, vma, extension_start, extension_end,
 					vma->vm_flags, vma->anon_vma, vma->vm_file,
 					extension_pgoff, vma_policy(vma),
 					vma->vm_userfaultfd_ctx, anon_vma_name(vma));
+			} else if (vma_adjust(vma, vma->vm_start, addr + new_len,
+				   vma->vm_pgoff, NULL)) {
+				vma = NULL;
+			}
 			if (!vma) {
 				vm_unacct_memory(pages);
 				ret = -ENOMEM;