[PATCH v2 31/31] selftests/mm: Add uffdio register ioctls test

From: Peter Xu
Date: Wed Apr 12 2023 - 12:48:22 EST


This new test tests against the returned ioctls from UFFDIO_REGISTER, where
put into uffdio_register.ioctls.

This also tests the expected failure cases of UFFDIO_REGISTER, aka:

- Register with empty mode should fail with -EINVAL
- Register minor without page cache (anon) should fail with -EINVAL

Signed-off-by: Peter Xu <peterx@xxxxxxxxxx>
---
tools/testing/selftests/mm/uffd-unit-tests.c | 112 ++++++++++++++++---
1 file changed, 97 insertions(+), 15 deletions(-)

diff --git a/tools/testing/selftests/mm/uffd-unit-tests.c b/tools/testing/selftests/mm/uffd-unit-tests.c
index b0acf558e8cb..d871bf732e62 100644
--- a/tools/testing/selftests/mm/uffd-unit-tests.c
+++ b/tools/testing/selftests/mm/uffd-unit-tests.c
@@ -62,8 +62,14 @@ mem_type_t mem_types[] = {
},
};

+/* Arguments to be passed over to each uffd unit test */
+struct uffd_test_args {
+ mem_type_t *mem_type;
+};
+typedef struct uffd_test_args uffd_test_args_t;
+
/* Returns: UFFD_TEST_* */
-typedef void (*uffd_test_fn)(void);
+typedef void (*uffd_test_fn)(uffd_test_args_t *);

typedef struct {
const char *name;
@@ -172,8 +178,9 @@ 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,
- const char **errmsg)
+static int
+uffd_setup_environment(uffd_test_args_t *args, 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;
@@ -187,6 +194,9 @@ 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;

+ /* Initialize test arguments */
+ args->mem_type = mem_type;
+
return uffd_test_ctx_init(test->uffd_feature_required, errmsg);
}

@@ -239,7 +249,7 @@ static int pagemap_test_fork(bool present)
return result;
}

-static void uffd_wp_unpopulated_test(void)
+static void uffd_wp_unpopulated_test(uffd_test_args_t *args)
{
uint64_t value;
int pagemap_fd;
@@ -285,7 +295,7 @@ static void uffd_wp_unpopulated_test(void)
uffd_test_pass();
}

-static void uffd_pagemap_test(void)
+static void uffd_pagemap_test(uffd_test_args_t *args)
{
int pagemap_fd;
uint64_t value;
@@ -415,17 +425,17 @@ static void uffd_minor_test_common(bool test_collapse, bool test_wp)
uffd_test_pass();
}

-void uffd_minor_test(void)
+void uffd_minor_test(uffd_test_args_t *args)
{
uffd_minor_test_common(false, false);
}

-void uffd_minor_wp_test(void)
+void uffd_minor_wp_test(uffd_test_args_t *args)
{
uffd_minor_test_common(false, true);
}

-void uffd_minor_collapse_test(void)
+void uffd_minor_collapse_test(uffd_test_args_t *args)
{
uffd_minor_test_common(true, false);
}
@@ -603,12 +613,12 @@ static void uffd_sigbus_test_common(bool wp)
uffd_test_pass();
}

-static void uffd_sigbus_test(void)
+static void uffd_sigbus_test(uffd_test_args_t *args)
{
uffd_sigbus_test_common(false);
}

-static void uffd_sigbus_wp_test(void)
+static void uffd_sigbus_wp_test(uffd_test_args_t *args)
{
uffd_sigbus_test_common(true);
}
@@ -651,12 +661,12 @@ static void uffd_events_test_common(bool wp)
uffd_test_pass();
}

-static void uffd_events_test(void)
+static void uffd_events_test(uffd_test_args_t *args)
{
uffd_events_test_common(false);
}

-static void uffd_events_wp_test(void)
+static void uffd_events_wp_test(uffd_test_args_t *args)
{
uffd_events_test_common(true);
}
@@ -724,7 +734,7 @@ uffd_register_detect_zeropage(int uffd, void *addr, uint64_t len)
}

/* exercise UFFDIO_ZEROPAGE */
-static void uffd_zeropage_test(void)
+static void uffd_zeropage_test(uffd_test_args_t *args)
{
bool has_zeropage;
int i;
@@ -748,7 +758,77 @@ static void uffd_zeropage_test(void)
uffd_test_pass();
}

+/*
+ * Test the returned uffdio_register.ioctls with different register modes.
+ * Note that _UFFDIO_ZEROPAGE is tested separately in the zeropage test.
+ */
+static void
+do_register_ioctls_test(uffd_test_args_t *args, bool miss, bool wp, bool minor)
+{
+ uint64_t ioctls = 0, expected = BIT_ULL(_UFFDIO_WAKE);
+ mem_type_t *mem_type = args->mem_type;
+ int ret;
+
+ ret = uffd_register_with_ioctls(uffd, area_dst, page_size,
+ miss, wp, minor, &ioctls);
+
+ /*
+ * Handle special cases of UFFDIO_REGISTER here where it should
+ * just fail with -EINVAL first..
+ *
+ * Case 1: register MINOR on anon
+ * Case 2: register with no mode selected
+ */
+ if ((minor && (mem_type->mem_flag == MEM_ANON)) ||
+ (!miss && !wp && !minor)) {
+ if (ret != -EINVAL)
+ err("register (miss=%d, wp=%d, minor=%d) failed "
+ "with wrong errno=%d", miss, wp, minor, ret);
+ return;
+ }
+
+ /* UFFDIO_REGISTER should succeed, then check ioctls returned */
+ if (miss)
+ expected |= BIT_ULL(_UFFDIO_COPY);
+ if (wp)
+ expected |= BIT_ULL(_UFFDIO_WRITEPROTECT);
+ if (minor)
+ expected |= BIT_ULL(_UFFDIO_CONTINUE);
+
+ if ((ioctls & expected) != expected)
+ err("unexpected uffdio_register.ioctls "
+ "(miss=%d, wp=%d, minor=%d): expected=0x%"PRIx64", "
+ "returned=0x%"PRIx64, miss, wp, minor, expected, ioctls);
+
+ if (uffd_unregister(uffd, area_dst, page_size))
+ err("unregister");
+}
+
+static void uffd_register_ioctls_test(uffd_test_args_t *args)
+{
+ int miss, wp, minor;
+
+ for (miss = 0; miss <= 1; miss++)
+ for (wp = 0; wp <= 1; wp++)
+ for (minor = 0; minor <= 1; minor++)
+ do_register_ioctls_test(args, miss, wp, minor);
+
+ uffd_test_pass();
+}
+
uffd_test_case_t uffd_tests[] = {
+ {
+ /* Test returned uffdio_register.ioctls. */
+ .name = "register-ioctls",
+ .uffd_fn = uffd_register_ioctls_test,
+ .mem_targets = MEM_ALL,
+ .uffd_feature_required = UFFD_FEATURE_MISSING_HUGETLBFS |
+ UFFD_FEATURE_MISSING_SHMEM |
+ UFFD_FEATURE_PAGEFAULT_FLAG_WP |
+ UFFD_FEATURE_WP_HUGETLBFS_SHMEM |
+ UFFD_FEATURE_MINOR_HUGETLBFS |
+ UFFD_FEATURE_MINOR_SHMEM,
+ },
{
.name = "zeropage",
.uffd_fn = uffd_zeropage_test,
@@ -835,6 +915,7 @@ int main(int argc, char *argv[])
int n_mems = sizeof(mem_types) / sizeof(mem_type_t);
uffd_test_case_t *test;
mem_type_t *mem_type;
+ uffd_test_args_t args;
char test_name[128];
const char *errmsg;
int has_uffd;
@@ -862,11 +943,12 @@ int main(int argc, char *argv[])
uffd_test_skip("feature missing");
continue;
}
- if (uffd_setup_environment(test, mem_type, &errmsg)) {
+ if (uffd_setup_environment(&args, test, mem_type,
+ &errmsg)) {
uffd_test_skip(errmsg);
continue;
}
- test->uffd_fn();
+ test->uffd_fn(&args);
}
}

--
2.39.1