[PATCH 20/29] selftests/mm: Allow allocate_area() to fail properly

Peter Xu
2023-03-30T16:12:35Z

Mostly to detect hugetlb allocation errors and skip hugetlb tests when
pages are not allocated.

Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/mm/uffd-common.c | 32 +++++++++++++++++-------
tools/testing/selftests/mm/uffd-common.h | 4 +--
2 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 92b7e00efa8a..ae6b61144b53 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -44,10 +44,13 @@ static void anon_release_pages(char *rel_area)
err("madvise(MADV_DONTNEED) failed");
}

-static void anon_allocate_area(void **alloc_area, bool is_src)
+static int anon_allocate_area(void **alloc_area, bool is_src)
{
*alloc_area = mmap(NULL, nr_pages * page_size, PROT_READ | PROT_WRITE,
MAP_ANONYMOUS | MAP_PRIVATE, -1, 0);
+ if (*alloc_area == MAP_FAILED)
+ err("ENOMEM");
+ return 0;
}

static void noop_alias_mapping(__u64 *start, size_t len, unsigned long offset)
@@ -65,7 +68,7 @@ static void hugetlb_release_pages(char *rel_area)
}
}

-static void hugetlb_allocate_area(void **alloc_area, bool is_src)
+static int hugetlb_allocate_area(void **alloc_area, bool is_src)
{
off_t size = nr_pages * page_size;
off_t offset = is_src ? 0 : size;
@@ -77,14 +80,16 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
(map_shared ? MAP_SHARED : MAP_PRIVATE) |
(is_src ? 0 : MAP_NORESERVE),
mem_fd, offset);
- if (*alloc_area == MAP_FAILED)
- err("mmap of hugetlbfs file failed");
+ if (*alloc_area == MAP_FAILED) {
+ *alloc_area = NULL;
+ return -errno;
+ }

if (map_shared) {
area_alias = mmap(NULL, size, PROT_READ | PROT_WRITE,
MAP_SHARED, mem_fd, offset);
if (area_alias == MAP_FAILED)
- err("mmap of hugetlb file alias failed");
+ return -errno;
}

if (is_src) {
@@ -96,6 +101,7 @@ static void hugetlb_allocate_area(void **alloc_area, bool is_src)
*alloc_area_alias = area_alias;

close(mem_fd);
+ return 0;
}

static void hugetlb_alias_mapping(__u64 *start, size_t len, unsigned long offset)
@@ -112,7 +118,7 @@ static void shmem_release_pages(char *rel_area)
err("madvise(MADV_REMOVE) failed");
}

-static void shmem_allocate_area(void **alloc_area, bool is_src)
+static int shmem_allocate_area(void **alloc_area, bool is_src)
{
void *area_alias = NULL;
size_t bytes = nr_pages * page_size, hpage_size = read_pmd_pagesize();
@@ -150,6 +156,7 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
area_dst_alias = area_alias;

close(mem_fd);
+ return 0;
}

static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
@@ -282,14 +289,19 @@ static void uffd_test_ctx_clear(void)
munmap_area((void **)&area_remap);
}

-void uffd_test_ctx_init(uint64_t features)
+int uffd_test_ctx_init(uint64_t features)
{
unsigned long nr, cpu;
+ int ret;

uffd_test_ctx_clear();

- uffd_test_ops->allocate_area((void **)&area_src, true);
- uffd_test_ops->allocate_area((void **)&area_dst, false);
+ ret = uffd_test_ops->allocate_area((void **)&area_src, true);
+ if (ret)
+ return ret;
+ ret = uffd_test_ops->allocate_area((void **)&area_dst, false);
+ if (ret)
+ return ret;

userfaultfd_open(&features);

@@ -337,6 +349,8 @@ void uffd_test_ctx_init(uint64_t features)
for (cpu = 0; cpu < nr_cpus; cpu++)
if (pipe2(&pipefd[cpu * 2], O_CLOEXEC | O_NONBLOCK))
err("pipe");
+
+ return 0;
}

void wp_range(int ufd, __u64 start, __u64 len, bool wp)
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
index f4bc73ce3b48..51ec75f6d0c1 100644
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -80,7 +80,7 @@ struct uffd_stats {
};

struct uffd_test_ops {
- void (*allocate_area)(void **alloc_area, bool is_src);
+ int (*allocate_area)(void **alloc_area, bool is_src);
void (*release_pages)(char *rel_area);
void (*alias_mapping)(__u64 *start, size_t len, unsigned long offset);
void (*check_pmd_mapping)(void *p, int expect_nr_hpages);
@@ -101,7 +101,7 @@ extern uffd_test_ops_t hugetlb_uffd_test_ops;
extern uffd_test_ops_t *uffd_test_ops;

void uffd_stats_report(struct uffd_stats *stats, int n_cpus);
-void uffd_test_ctx_init(uint64_t features);
+int uffd_test_ctx_init(uint64_t features);
void 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);
--
2.39.1