selftests/mm: allow allocate_area() to fail properly

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

Link: https://lkml.kernel.org/r/20230412164345.328659-1-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Dmitry Safonov <0x7f454c46@gmail.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index daa2a95408e601fd85a4bbdaa31480d32a3641f0..bc6c5c38d6dd7b8cef6acedbe7973561083873c4 100644 (file)
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -44,10 +44,15 @@ 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) {
+               *alloc_area = NULL;
+               return -errno;
+       }
+       return 0;
 }
 
 static void noop_alias_mapping(__u64 *start, size_t len, unsigned long offset)
@@ -65,7 +70,7 @@ 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 +82,16 @@ 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 +103,7 @@ 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 +120,7 @@ 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();
@@ -132,15 +140,20 @@ static void shmem_allocate_area(void **alloc_area, bool is_src)
 
        *alloc_area = mmap(p, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
                           mem_fd, offset);
-       if (*alloc_area == MAP_FAILED)
-               err("mmap of memfd failed");
+       if (*alloc_area == MAP_FAILED) {
+               *alloc_area = NULL;
+               return -errno;
+       }
        if (test_collapse && *alloc_area != p)
                err("mmap of memfd failed at %p", p);
 
        area_alias = mmap(p_alias, bytes, PROT_READ | PROT_WRITE, MAP_SHARED,
                          mem_fd, offset);
-       if (area_alias == MAP_FAILED)
-               err("mmap of memfd alias failed");
+       if (area_alias == MAP_FAILED) {
+               munmap(*alloc_area, bytes);
+               *alloc_area = NULL;
+               return -errno;
+       }
        if (test_collapse && area_alias != p_alias)
                err("mmap of anonymous memory failed at %p", p_alias);
 
@@ -150,6 +163,7 @@ 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 +296,19 @@ 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 +356,8 @@ 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 0ec07d025cfe07318e0cde1a0f8d1ce1975b3fb0..9479a0649d7fec63d98522dc9ee1b45a61bd6857 100644 (file)
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -80,7 +80,7 @@ struct uffd_args {
 };
 
 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_args *args, 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);