The patch titled
Subject: userfaultfd: selftests: modify selftest to use /dev/userfaultfd
has been added to the -mm mm-unstable branch. Its filename is
userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.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: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Subject: userfaultfd: selftests: modify selftest to use /dev/userfaultfd
Date: Wed, 1 Jun 2022 14:09:48 -0700
We clearly want to ensure both userfaultfd(2) and /dev/userfaultfd keep
working into the future, so just run the test twice, using each interface.
Link: https://lkml.kernel.org/r/20220601210951.3916598-4-axelrasmussen@xxxxxxxxxx
Signed-off-by: Axel Rasmussen <axelrasmussen@xxxxxxxxxx>
Cc: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
Cc: Charan Teja Kalla <charante@xxxxxxxxxxxxxx>
Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Cc: Dmitry V. Levin <ldv@xxxxxxxxxxxx>
Cc: Gleb Fotengauer-Malinovskiy <glebfm@xxxxxxxxxxxx>
Cc: Hugh Dickins <hughd@xxxxxxxxxx>
Cc: Jan Kara <jack@xxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx>
Cc: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxx>
Cc: Nadav Amit <namit@xxxxxxxxxx>
Cc: Peter Xu <peterx@xxxxxxxxxx>
Cc: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
Cc: Suren Baghdasaryan <surenb@xxxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Zhang Yi <yi.zhang@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
tools/testing/selftests/vm/userfaultfd.c | 37 ++++++++++++++++++---
1 file changed, 33 insertions(+), 4 deletions(-)
--- a/tools/testing/selftests/vm/userfaultfd.c~userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd
+++ a/tools/testing/selftests/vm/userfaultfd.c
@@ -77,6 +77,9 @@ static int bounces;
#define TEST_SHMEM 3
static int test_type;
+/* test using /dev/userfaultfd, instead of userfaultfd(2) */
+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;
@@ -154,12 +157,14 @@ static void usage(void)
ret, __LINE__); \
} while (0)
-#define err(fmt, ...) \
+#define errexit(exitcode, fmt, ...) \
do { \
_err(fmt, ##__VA_ARGS__); \
- exit(1); \
+ exit(exitcode); \
} while (0)
+#define err(fmt, ...) errexit(1, fmt, ##__VA_ARGS__)
+
static void uffd_stats_reset(struct uffd_stats *uffd_stats,
unsigned long n_cpus)
{
@@ -383,13 +388,31 @@ static void assert_expected_ioctls_prese
}
}
+static void __userfaultfd_open_dev(void)
+{
+ int fd;
+
+ uffd = -1;
+ fd = open("/dev/userfaultfd", O_RDWR | O_CLOEXEC);
+ if (fd < 0)
+ return;
+
+ uffd = ioctl(fd, USERFAULTFD_IOC_NEW,
+ O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
+ close(fd);
+}
+
static void userfaultfd_open(uint64_t *features)
{
struct uffdio_api uffdio_api;
- uffd = syscall(__NR_userfaultfd, O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
+ if (test_dev_userfaultfd)
+ __userfaultfd_open_dev();
+ else
+ uffd = syscall(__NR_userfaultfd,
+ O_CLOEXEC | O_NONBLOCK | UFFD_USER_MODE_ONLY);
if (uffd < 0)
- err("userfaultfd syscall not available in this kernel");
+ errexit(KSFT_SKIP, "creating userfaultfd failed");
uffd_flags = fcntl(uffd, F_GETFD, NULL);
uffdio_api.api = UFFD_API;
@@ -1691,6 +1714,12 @@ int main(int argc, char **argv)
}
printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n",
nr_pages, nr_pages_per_cpu);
+
+ test_dev_userfaultfd = false;
+ if (userfaultfd_stress())
+ return 1;
+
+ test_dev_userfaultfd = true;
return userfaultfd_stress();
}
_
Patches currently in -mm which might be from axelrasmussen@xxxxxxxxxx are
mm-userfaultfd-fix-uffdio_continue-on-fallocated-shmem-pages.patch
selftests-vm-add-hugetlb_shared-userfaultfd-test-to-run_vmtestssh.patch
userfaultfd-add-dev-userfaultfd-for-fine-grained-access-control.patch
userfaultfd-selftests-modify-selftest-to-use-dev-userfaultfd.patch
userfaultfd-update-documentation-to-describe-dev-userfaultfd.patch
userfaultfd-selftests-make-dev-userfaultfd-testing-configurable.patch
selftests-vm-add-dev-userfaultfd-test-cases-to-run_vmtestssh.patch
