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

Mike Rapoport
2023-04-11T11:04:05Z

On Thu, Mar 30, 2023 at 12:08:15PM -0400, Peter Xu wrote:
> Mostly to detect hugetlb allocation errors and skip hugetlb tests when
> pages are not allocated.

Wouldn't we want to skip anon and shmem tests as well for consistency?

> 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
>

--
Sincerely yours,
Mike.