+ selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: selftests/mm: call uffd_test_ctx_clear at the end of the test
has been added to the -mm mm-unstable branch.  Its filename is
     selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Suren Baghdasaryan <surenb@google.com>
Subject: selftests/mm: call uffd_test_ctx_clear at the end of the test
Date: Tue, 21 Nov 2023 09:16:36 -0800

uffd_test_ctx_clear() is being called from uffd_test_ctx_init() to unmap
areas used in the previous test run.  This approach is problematic because
while unmapping areas uffd_test_ctx_clear() uses page_size and nr_pages
which might differ from one test run to another.  Fix this by calling
uffd_test_ctx_clear() after each test is done.

Link: https://lkml.kernel.org/r/20231121171643.3719880-4-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmussen@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Brian Geffon <bgeffon@google.com>
Cc: Christian Brauner <brauner@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Cc: Lokesh Gidra <lokeshgidra@google.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Nicolas Geoffray <ngeoffray@google.com>
Cc: Shuah Khan <shuah@kernel.org>
Cc: ZhangPeng <zhangpeng362@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 tools/testing/selftests/mm/uffd-common.c     |    4 +---
 tools/testing/selftests/mm/uffd-common.h     |    1 +
 tools/testing/selftests/mm/uffd-stress.c     |    5 ++++-
 tools/testing/selftests/mm/uffd-unit-tests.c |    1 +
 4 files changed, 7 insertions(+), 4 deletions(-)

--- a/tools/testing/selftests/mm/uffd-common.c~selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test
+++ a/tools/testing/selftests/mm/uffd-common.c
@@ -262,7 +262,7 @@ static inline void munmap_area(void **ar
 	*area = NULL;
 }
 
-static void uffd_test_ctx_clear(void)
+void uffd_test_ctx_clear(void)
 {
 	size_t i;
 
@@ -298,8 +298,6 @@ int uffd_test_ctx_init(uint64_t features
 	unsigned long nr, cpu;
 	int ret;
 
-	uffd_test_ctx_clear();
-
 	ret = uffd_test_ops->allocate_area((void **)&area_src, true);
 	ret |= uffd_test_ops->allocate_area((void **)&area_dst, false);
 	if (ret) {
--- a/tools/testing/selftests/mm/uffd-common.h~selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test
+++ a/tools/testing/selftests/mm/uffd-common.h
@@ -105,6 +105,7 @@ extern uffd_test_ops_t *uffd_test_ops;
 
 void uffd_stats_report(struct uffd_args *args, int n_cpus);
 int uffd_test_ctx_init(uint64_t features, const char **errmsg);
+void uffd_test_ctx_clear(void);
 int userfaultfd_open(uint64_t *features);
 int uffd_read_msg(int ufd, struct uffd_msg *msg);
 void wp_range(int ufd, __u64 start, __u64 len, bool wp);
--- a/tools/testing/selftests/mm/uffd-stress.c~selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test
+++ a/tools/testing/selftests/mm/uffd-stress.c
@@ -323,8 +323,10 @@ static int userfaultfd_stress(void)
 		uffd_stats_reset(args, nr_cpus);
 
 		/* bounce pass */
-		if (stress(args))
+		if (stress(args)) {
+			uffd_test_ctx_clear();
 			return 1;
+		}
 
 		/* Clear all the write protections if there is any */
 		if (test_uffdio_wp)
@@ -354,6 +356,7 @@ static int userfaultfd_stress(void)
 
 		uffd_stats_report(args, nr_cpus);
 	}
+	uffd_test_ctx_clear();
 
 	return 0;
 }
--- a/tools/testing/selftests/mm/uffd-unit-tests.c~selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test
+++ a/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -1319,6 +1319,7 @@ int main(int argc, char *argv[])
 				continue;
 			}
 			test->uffd_fn(&args);
+			uffd_test_ctx_clear();
 		}
 	}
 
_

Patches currently in -mm which might be from surenb@google.com are

selftests-mm-call-uffd_test_ctx_clear-at-the-end-of-the-test.patch
selftests-mm-add-uffd_test_case_ops-to-allow-test-case-specific-operations.patch
selftests-mm-add-uffdio_move-ioctl-test.patch