[PATCH 11/29] selftests/mm: Drop test_uffdio_zeropage_eexist

Peter Xu
2023-03-30T16:08:29Z

The idea was trying to flip this var in the alarm handler from time to time
to test -EEXIST of UFFDIO_ZEROPAGE, but firstly it's only used in the
zeropage test so probably only used once, meanwhile we passed
"retry==false" so it'll never got tested anyway.

Drop both sides so we always test UFFDIO_ZEROPAGE retries if has_zeropage
is set (!hugetlb).

One more thing to do is doing UFFDIO_REGISTER for the alias buffer too,
because otherwise the test won't even pass! We were just lucky that this
test never really got ran at all.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/mm/userfaultfd.c | 20 +++++++++++---------
1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/mm/userfaultfd.c b/tools/testing/selftests/mm/userfaultfd.c
index d724f1c78847..3487ec0bfcc8 100644
--- a/tools/testing/selftests/mm/userfaultfd.c
+++ b/tools/testing/selftests/mm/userfaultfd.c
@@ -88,7 +88,6 @@ static bool test_dev_userfaultfd;
/* exercise the test_uffdio_*_eexist every ALARM_INTERVAL_SECS */
#define ALARM_INTERVAL_SECS 10
static volatile bool test_uffdio_copy_eexist = true;
-static volatile bool test_uffdio_zeropage_eexist = true;
/* Whether to test uffd write-protection */
static bool test_uffdio_wp = true;
/* Whether to test uffd minor faults */
@@ -1114,7 +1113,7 @@ static void retry_uffdio_zeropage(int ufd,
}
}

-static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry)
+static int __uffdio_zeropage(int ufd, unsigned long offset)
{
struct uffdio_zeropage uffdio_zeropage;
int ret;
@@ -1138,11 +1137,8 @@ static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry)
if (res != page_size) {
err("UFFDIO_ZEROPAGE unexpected size");
} else {
- if (test_uffdio_zeropage_eexist && retry) {
- test_uffdio_zeropage_eexist = false;
- retry_uffdio_zeropage(ufd, &uffdio_zeropage,
- offset);
- }
+ retry_uffdio_zeropage(ufd, &uffdio_zeropage,
+ offset);
return 1;
}
} else
@@ -1153,7 +1149,7 @@ static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry)

static int uffdio_zeropage(int ufd, unsigned long offset)
{
- return __uffdio_zeropage(ufd, offset, false);
+ return __uffdio_zeropage(ufd, offset);
}

/* exercise UFFDIO_ZEROPAGE */
@@ -1177,6 +1173,13 @@ static int userfaultfd_zeropage_test(void)
assert_expected_ioctls_present(
uffdio_register.mode, uffdio_register.ioctls);

+ if (area_dst_alias) {
+ /* Needed this to test zeropage-retry on shared memory */
+ uffdio_register.range.start = (unsigned long) area_dst_alias;
+ if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
+ err("register failure");
+ }
+
if (uffdio_zeropage(uffd, 0))
if (my_bcmp(area_dst, zeropage, page_size))
err("zeropage is not zero");
@@ -1763,7 +1766,6 @@ static void sigalrm(int sig)
if (sig != SIGALRM)
abort();
test_uffdio_copy_eexist = true;
- test_uffdio_zeropage_eexist = true;
alarm(ALARM_INTERVAL_SECS);
}

--
2.39.1