[PATCH 17/29] selftests/mm: Drop global mem_fd in uffd tests

Peter Xu
2023-03-30T16:09:46Z

Drop it by creating the memfd dynamically in the tests.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/mm/uffd-common.c | 28 +++++++++++++++++++++++-
tools/testing/selftests/mm/uffd-common.h | 2 +-
tools/testing/selftests/mm/uffd-stress.c | 15 -------------
3 files changed, 28 insertions(+), 17 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 3a9b5c1aca9d..a2b6e4957d0f 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -12,12 +12,32 @@
volatile bool test_uffdio_copy_eexist = true;
unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size, hpage_size;
char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap;
-int mem_fd, uffd = -1, uffd_flags, finished, *pipefd, test_type;
+int uffd = -1, uffd_flags, finished, *pipefd, test_type;
bool map_shared, test_collapse, test_dev_userfaultfd;
bool test_uffdio_wp = true, test_uffdio_minor = false;
unsigned long long *count_verify;
uffd_test_ops_t *uffd_test_ops;

+static int uffd_mem_fd_create(off_t mem_size, bool hugetlb)
+{
+ unsigned int memfd_flags = 0;
+ int mem_fd;
+
+ if (hugetlb)
+ memfd_flags = MFD_HUGETLB;
+ mem_fd = memfd_create("uffd-test", memfd_flags);
+ if (mem_fd < 0)
+ err("memfd_create");
+ if (ftruncate(mem_fd, mem_size))
+ err("ftruncate");
+ if (fallocate(mem_fd,
+ FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
+ mem_size))
+ err("fallocate");
+
+ return mem_fd;
+}
+
static void anon_release_pages(char *rel_area)
{
if (madvise(rel_area, nr_pages * page_size, MADV_DONTNEED))
@@ -51,6 +71,7 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
off_t offset = is_src ? 0 : size;
void *area_alias = NULL;
char **alloc_area_alias;
+ int mem_fd = uffd_mem_fd_create(size * 2, true);

*alloc_area = mmap(NULL, size, PROT_READ | PROT_WRITE,
(map_shared ? MAP_SHARED : MAP_PRIVATE) |
@@ -73,6 +94,8 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
}
if (area_alias)
*alloc_area_alias = area_alias;
+
+ close(mem_fd);
}

static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset)
@@ -95,6 +118,7 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
size_t bytes = nr_pages * page_size;
unsigned long offset = is_src ? 0 : bytes;
char *p = NULL, *p_alias = NULL;
+ int mem_fd = uffd_mem_fd_create(bytes * 2, false);

if (test_collapse) {
p = BASE_PMD_ADDR;
@@ -124,6 +148,8 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
area_src_alias = area_alias;
else
area_dst_alias = area_alias;
+
+ close(mem_fd);
}

static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
index 11f770391bd9..0dfab7057295 100644
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -87,7 +87,7 @@ typedef struct uffd_test_ops uffd_test_ops_t;

extern unsigned long nr_cpus, nr_pages, nr_pages_per_cpu, page_size, hpage_size;
extern char *area_src, *area_src_alias, *area_dst, *area_dst_alias, *area_remap;
-extern int mem_fd, uffd, uffd_flags, finished, *pipefd, test_type;
+extern int uffd, uffd_flags, finished, *pipefd, test_type;
extern bool map_shared, test_collapse, test_dev_userfaultfd;
extern bool test_uffdio_wp, test_uffdio_minor;
extern unsigned long long *count_verify;
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index e6d39a755082..4eca1a0276c2 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -1090,21 +1090,6 @@ int main(int argc, char **argv)
}
nr_pages = nr_pages_per_cpu * nr_cpus;

- if (test_type == TEST_SHMEM || test_type == TEST_HUGETLB) {
- unsigned int memfd_flags = 0;
-
- if (test_type == TEST_HUGETLB)
- memfd_flags = MFD_HUGETLB;
- mem_fd = memfd_create(argv[0], memfd_flags);
- if (mem_fd < 0)
- err("memfd_create");
- if (ftruncate(mem_fd, nr_pages * page_size * 2))
- err("ftruncate");
- if (fallocate(mem_fd,
- FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0,
- nr_pages * page_size * 2))
- err("fallocate");
- }
printf("nr_pages: %lu, nr_pages_per_cpu: %lu\n",
nr_pages, nr_pages_per_cpu);
return userfaultfd_stress();
--
2.39.1