From 6694afe31dd67d186199a58d2252be5ea3472692 Mon Sep 17 00:00:00 2001

From: Dan Williams <dan.j.williams@intel.com>

Date: Tue, 12 Jan 2021 23:15:09 -0800

Subject: [PATCH 005/217] ndctl/test: Fix device-dax mremap() test

The test_dax_remap() test is a regression check for mishandling of mremap()

in the presence of pmd_devmap(). My understanding is that it was a fuzzing

condition not something an application would want to do in practice.

On recent kernels with commit 73d5e0629919 ("mremap: check if it's possible

to split original vma"), the test fails for device-dax. That seems an

equally acceptable result of attempting this remap, so update the test

rather than ask the kernel to preserve the old behaviour.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>

Signed-off-by: Vishal Verma <vishal.l.verma@intel.com>

Link: https://lore.kernel.org/r/161052210936.1804207.17896246772670985157.stgit@dwillia2-desk3.amr.corp.intel.com

---

 test/dax-pmd.c | 5 +++++

 1 file changed, 5 insertions(+)

diff --git a/test/dax-pmd.c b/test/dax-pmd.c

index b1251db..7648e34 100644

--- a/test/dax-pmd.c

+++ b/test/dax-pmd.c

@@ -69,6 +69,11 @@ int test_dax_remap(struct ndctl_test *test, int dax_fd, unsigned long align, voi

 	remap = mremap(addr, REMAP_SIZE, REMAP_SIZE, MREMAP_MAYMOVE|MREMAP_FIXED, anon);

+	if (remap == MAP_FAILED) {

+		fprintf(stderr, "%s: mremap failed, that's ok too\n", __func__);

+		return 0;

+	}

+

 	if (remap != anon) {

 		rc = -ENXIO;

 		perror("mremap");

-- 

2.27.0