[PATCH v6 3/5] selftests/mm: call uffd_test_ctx_clear at the end of the test

[Suren Baghdasaryan]

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.

Signed-off-by: Suren Baghdasaryan <sur...@google.com>
Reviewed-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Axel Rasmussen <axelrasmus...@google.com>
---
 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(-)

diff --git a/tools/testing/selftests/mm/uffd-common.c 
b/tools/testing/selftests/mm/uffd-common.c
index 02b89860e193..583e5a4cc0fd 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -262,7 +262,7 @@ static inline void munmap_area(void **area)
        *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, const char 
**errmsg)
        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) {
diff --git a/tools/testing/selftests/mm/uffd-common.h 
b/tools/testing/selftests/mm/uffd-common.h
index 7c4fa964c3b0..870776b5a323 100644
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/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);
diff --git a/tools/testing/selftests/mm/uffd-stress.c 
b/tools/testing/selftests/mm/uffd-stress.c
index 469e0476af26..7e83829bbb33 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/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;
 }
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c 
b/tools/testing/selftests/mm/uffd-unit-tests.c
index 2709a34a39c5..e7d43c198041 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/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();
                }
        }
 
-- 
2.43.0.rc2.451.g8631bc7472-goog