[PATCH 2/2] Update uffd-stress to handle EINVAL for unset config features

From: Audra Mitchell
Date: Tue May 07 2024 - 16:06:43 EST


Now that we have updated userfaultfd_api to correctly return
EIVAL when a feature is requested but not available, let's fix
the uffd-stress test to only set the UFFD_FEATURE_WP_UNPOPULATED
feature when the config is set. In addition, still run the test if
the CONFIG_PTE_MARKER_UFFD_WP is not set, just dont use the corresponding
UFFD_FEATURE_WP_UNPOPULATED feature.

Signed-off-by: Audra Mitchell <audra@xxxxxxxxxx>
---
tools/testing/selftests/mm/uffd-stress.c | 14 +++++++++-----
1 file changed, 9 insertions(+), 5 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-stress.c b/tools/testing/selftests/mm/uffd-stress.c
index f78bab0f3d45..b9b6d858eab8 100644
--- a/tools/testing/selftests/mm/uffd-stress.c
+++ b/tools/testing/selftests/mm/uffd-stress.c
@@ -38,6 +38,8 @@

#ifdef __NR_userfaultfd

+uint64_t features;
+
#define BOUNCE_RANDOM (1<<0)
#define BOUNCE_RACINGFAULTS (1<<1)
#define BOUNCE_VERIFY (1<<2)
@@ -247,10 +249,14 @@ static int userfaultfd_stress(void)
unsigned long nr;
struct uffd_args args[nr_cpus];
uint64_t mem_size = nr_pages * page_size;
+ int flags = 0;

memset(args, 0, sizeof(struct uffd_args) * nr_cpus);

- if (uffd_test_ctx_init(UFFD_FEATURE_WP_UNPOPULATED, NULL))
+ if (features & UFFD_FEATURE_WP_UNPOPULATED && test_type == TEST_ANON)
+ flags = UFFD_FEATURE_WP_UNPOPULATED;
+
+ if (uffd_test_ctx_init(flags, NULL))
err("context init failed");

if (posix_memalign(&area, page_size, page_size))
@@ -385,8 +391,6 @@ static void set_test_type(const char *type)

static void parse_test_type_arg(const char *raw_type)
{
- uint64_t features = UFFD_API_FEATURES;
-
set_test_type(raw_type);

if (!test_type)
@@ -409,8 +413,8 @@ static void parse_test_type_arg(const char *raw_type)
* feature.
*/

- if (userfaultfd_open(&features))
- err("Userfaultfd open failed");
+ if (uffd_get_features(&features))
+ err("failed to get available features");

test_uffdio_wp = test_uffdio_wp &&
(features & UFFD_FEATURE_PAGEFAULT_FLAG_WP);
--
2.44.0