[PATCH 27/29] selftests/mm: Allow uffd test to skip properly with no privilege

Peter Xu
2023-03-30T16:13:57Z

Allow skip a unit test properly due to no privilege (e.g. sigbus and events
tests).

Signed-off-by: Peter Xu <peterx@redhat.com>
---
tools/testing/selftests/mm/uffd-common.c | 27 ++++++++++++--------
tools/testing/selftests/mm/uffd-common.h | 4 +--
tools/testing/selftests/mm/uffd-stress.c | 6 +++--
tools/testing/selftests/mm/uffd-unit-tests.c | 10 +++++---
4 files changed, 29 insertions(+), 18 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-common.c b/tools/testing/selftests/mm/uffd-common.c
index 95ad619d0df4..964fa57b710a 100644
--- a/tools/testing/selftests/mm/uffd-common.c
+++ b/tools/testing/selftests/mm/uffd-common.c
@@ -225,7 +225,7 @@ void uffd_stats_report(struct uffd_stats *stats, int n_cpus)
printf("\n");
}

-void userfaultfd_open(uint64_t *features)
+int userfaultfd_open(uint64_t *features)
{
struct uffdio_api uffdio_api;

@@ -234,18 +234,19 @@ void userfaultfd_open(uint64_t *features)
else
uffd = uffd_open_sys(UFFD_FLAGS);
if (uffd < 0)
- err("uffd open failed (dev=%d)", test_dev_userfaultfd);
+ return -1;
uffd_flags = fcntl(uffd, F_GETFD, NULL);

uffdio_api.api = UFFD_API;
uffdio_api.features = *features;
if (ioctl(uffd, UFFDIO_API, &uffdio_api))
- err("UFFDIO_API failed.\nPlease make sure to "
- "run with either root or ptrace capability.");
+ /* Probably lack of CAP_PTRACE? */
+ return -1;
if (uffdio_api.api != UFFD_API)
err("UFFDIO_API error: %" PRIu64, (uint64_t)uffdio_api.api);

*features = uffdio_api.features;
+ return 0;
}

static inline void munmap_area(void **area)
@@ -288,7 +289,7 @@ static void uffd_test_ctx_clear(void)
munmap_area((void **)&area_remap);
}

-int uffd_test_ctx_init(uint64_t features)
+int uffd_test_ctx_init(uint64_t features, const char **errmsg)
{
unsigned long nr, cpu;
int ret;
@@ -296,13 +297,19 @@ int uffd_test_ctx_init(uint64_t features)
uffd_test_ctx_clear();

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)
+ ret |= uffd_test_ops->allocate_area((void **)&area_dst, false);
+ if (ret) {
+ if (errmsg)
+ *errmsg = "memory allocation failed";
return ret;
+ }

- userfaultfd_open(&features);
+ ret = userfaultfd_open(&features);
+ if (ret) {
+ if (errmsg)
+ *errmsg = "possible lack of priviledge";
+ return ret;
+ }

count_verify = malloc(nr_pages * sizeof(unsigned long long));
if (!count_verify)
diff --git a/tools/testing/selftests/mm/uffd-common.h b/tools/testing/selftests/mm/uffd-common.h
index 16d32ddf8412..07d00e9809dc 100644
--- a/tools/testing/selftests/mm/uffd-common.h
+++ b/tools/testing/selftests/mm/uffd-common.h
@@ -101,8 +101,8 @@ 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);
-int uffd_test_ctx_init(uint64_t features);
-void userfaultfd_open(uint64_t *features);
+int uffd_test_ctx_init(uint64_t features, const char **errmsg);
+int 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);
void uffd_handle_page_fault(struct uffd_msg *msg, struct uffd_stats *stats);
diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index a6f3609c1ad1..8f41bef2fbda 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -272,7 +272,8 @@ static int userfaultfd_stress(void)
struct uffd_stats uffd_stats[nr_cpus];
uint64_t mem_size = nr_pages * page_size;

- uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED);
+ if (uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED, NULL))
+ err("context init failed");

if (posix_memalign(&area, page_size, page_size))
err("out of memory");
@@ -436,7 +437,8 @@ static void parse_test_type_arg(const char *raw_type)
* feature.
*/

- userfaultfd_open(&features);
+ if (userfaultfd_open(&features))
+ err("Userfaultfd open failed");

test_uffdio_wp = test_uffdio_wp &&
(features & UFFD_FEATURE_PAGEFAULT_FLAG_WP);
diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index 82fd3aaa06c2..9e7f7c7f2982 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -175,7 +175,8 @@ static int test_uffd_api(bool use_dev)
* This function initializes the global variables. TODO: remove global
* vars and then remove this.
*/
-static int uffd_setup_environment(uffd_test_case_t *test, mem_type_t *mem_type)
+static int uffd_setup_environment(uffd_test_case_t *test, mem_type_t *mem_type,
+ const char **errmsg)
{
map_shared = mem_type->shared;
uffd_test_ops = mem_type->mem_ops;
@@ -189,7 +190,7 @@ static int uffd_setup_environment(uffd_test_case_t *test, mem_type_t *mem_type)
/* TODO: remove this global var.. it's so ugly */
nr_cpus = 1;

- return uffd_test_ctx_init(test->uffd_feature_required);
+ return uffd_test_ctx_init(test->uffd_feature_required, errmsg);
}

static bool uffd_feature_supported(uffd_test_case_t *test)
@@ -838,6 +839,7 @@ int main(int argc, char *argv[])
uffd_test_case_t *test;
mem_type_t *mem_type;
char test_name[128];
+ const char *errmsg;
int has_uffd;
int i, j;

@@ -863,8 +865,8 @@ int main(int argc, char *argv[])
uffd_test_skip("feature missing");
continue;
}
- if (uffd_setup_environment(test, mem_type)) {
- uffd_test_skip("memory allocation failed");
+ if (uffd_setup_environment(test, mem_type, &errmsg)) {
+ uffd_test_skip(errmsg);
continue;
}
test->uffd_fn();
--
2.39.1