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Message-Id: <20210921163323.944352-2-axelrasmussen@google.com>
Date: Tue, 21 Sep 2021 09:33:22 -0700
From: Axel Rasmussen <axelrasmussen@...gle.com>
To: Andrew Morton <akpm@...ux-foundation.org>,
Peter Xu <peterx@...hat.com>, Shuah Khan <shuah@...nel.org>
Cc: linux-mm@...ck.org, linux-kselftest@...r.kernel.org,
linux-kernel@...r.kernel.org,
Axel Rasmussen <axelrasmussen@...gle.com>
Subject: [PATCH 2/3] userfaultfd/selftests: fix calculation of expected ioctls
Currently, the list of expected ioctls is stored in uffd_test_ops. This
design comes with the implicit assumption that the set of expected ioctls
is a function of the memory type (anon, shmem, or hugetlb).
However, this is not the case. For example:
- UFFDIO_WRITEPROTECT is supported for anon in general, *but not on
aarch64* (which lacks CONFIG_HAVE_ARCH_USERFAULTFD_WP).
- UFFDIO_WRITEPROTECT is supported for anon, but only if one registers
the region with UFFD_REGISTER_MODE_WP.
- We want to test (and expect) UFFDIO_CONTINUE, but only for *shared*
hugetlb, not private.
So, instead, remove the set of expected ioctls from this structure.
Define a new function which can compute the correct set by examining
the memory type, the userfaultfd registration mode(s), whether map_shared
is set, and what set of features the kernel reports as supported (from
UFFDIO_API).
In addition to being more correct, this improves code re-use - less
boilerplate in each test trying to perform this assertion.
Signed-off-by: Axel Rasmussen <axelrasmussen@...gle.com>
---
tools/testing/selftests/vm/userfaultfd.c | 103 ++++++++++++-----------
1 file changed, 56 insertions(+), 47 deletions(-)
diff --git a/tools/testing/selftests/vm/userfaultfd.c b/tools/testing/selftests/vm/userfaultfd.c
index 2366caf90435..aad5211f5012 100644
--- a/tools/testing/selftests/vm/userfaultfd.c
+++ b/tools/testing/selftests/vm/userfaultfd.c
@@ -304,37 +304,24 @@ static void shmem_alias_mapping(__u64 *start, size_t len, unsigned long offset)
}
struct uffd_test_ops {
- unsigned long expected_ioctls;
void (*allocate_area)(void **alloc_area);
void (*release_pages)(char *rel_area);
void (*alias_mapping)(__u64 *start, size_t len, unsigned long offset);
};
-#define SHMEM_EXPECTED_IOCTLS ((1 << _UFFDIO_WAKE) | \
- (1 << _UFFDIO_COPY) | \
- (1 << _UFFDIO_ZEROPAGE))
-
-#define ANON_EXPECTED_IOCTLS ((1 << _UFFDIO_WAKE) | \
- (1 << _UFFDIO_COPY) | \
- (1 << _UFFDIO_ZEROPAGE) | \
- (1 << _UFFDIO_WRITEPROTECT))
-
static struct uffd_test_ops anon_uffd_test_ops = {
- .expected_ioctls = ANON_EXPECTED_IOCTLS,
.allocate_area = anon_allocate_area,
.release_pages = anon_release_pages,
.alias_mapping = noop_alias_mapping,
};
static struct uffd_test_ops shmem_uffd_test_ops = {
- .expected_ioctls = SHMEM_EXPECTED_IOCTLS,
.allocate_area = shmem_allocate_area,
.release_pages = shmem_release_pages,
.alias_mapping = shmem_alias_mapping,
};
static struct uffd_test_ops hugetlb_uffd_test_ops = {
- .expected_ioctls = UFFD_API_RANGE_IOCTLS_BASIC & ~(1 << _UFFDIO_CONTINUE),
.allocate_area = hugetlb_allocate_area,
.release_pages = hugetlb_release_pages,
.alias_mapping = hugetlb_alias_mapping,
@@ -368,6 +355,47 @@ static inline bool uffd_wp_supported(void)
(uffd_features & UFFD_FEATURE_PAGEFAULT_FLAG_WP);
}
+static inline uint64_t uffd_minor_feature(void)
+{
+ if (test_type == TEST_HUGETLB && map_shared)
+ return UFFD_FEATURE_MINOR_HUGETLBFS;
+ else if (test_type == TEST_SHMEM)
+ return UFFD_FEATURE_MINOR_SHMEM;
+ else
+ return 0;
+}
+
+static inline bool uffd_minor_supported(void)
+{
+ return uffd_features & uffd_minor_feature();
+}
+
+static unsigned long get_expected_ioctls(uint64_t mode)
+{
+ unsigned long ioctls = UFFD_API_RANGE_IOCTLS;
+
+ if (test_type == TEST_HUGETLB)
+ ioctls &= ~(1 << _UFFDIO_ZEROPAGE);
+
+ if (!((mode & UFFDIO_REGISTER_MODE_WP) && uffd_wp_supported()))
+ ioctls &= ~(1 << _UFFDIO_WRITEPROTECT);
+
+ if (!((mode & UFFDIO_REGISTER_MODE_MINOR) && uffd_minor_supported()))
+ ioctls &= ~(1 << _UFFDIO_CONTINUE);
+
+ return ioctls;
+}
+
+static inline void assert_expected_ioctls_present(uint64_t mode, uint64_t ioctls)
+{
+ uint64_t expected = get_expected_ioctls(mode);
+ uint64_t actual = ioctls & expected;
+
+ if (actual != expected)
+ err("missing ioctl(s); expected: %"PRIx64" actual: %"PRIx64,
+ expected, actual);
+}
+
static inline void munmap_area(void **area)
{
if (*area)
@@ -1012,11 +1040,9 @@ static int __uffdio_zeropage(int ufd, unsigned long offset, bool retry)
{
struct uffdio_zeropage uffdio_zeropage;
int ret;
- unsigned long has_zeropage;
+ bool has_zeropage = get_expected_ioctls(0) & (1 << _UFFDIO_ZEROPAGE);
__s64 res;
- has_zeropage = uffd_test_ops->expected_ioctls & (1 << _UFFDIO_ZEROPAGE);
-
if (offset >= nr_pages * page_size)
err("unexpected offset %lu", offset);
uffdio_zeropage.range.start = (unsigned long) area_dst + offset;
@@ -1056,7 +1082,6 @@ static int uffdio_zeropage(int ufd, unsigned long offset)
static int userfaultfd_zeropage_test(void)
{
struct uffdio_register uffdio_register;
- unsigned long expected_ioctls;
printf("testing UFFDIO_ZEROPAGE: ");
fflush(stdout);
@@ -1071,9 +1096,8 @@ static int userfaultfd_zeropage_test(void)
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
err("register failure");
- expected_ioctls = uffd_test_ops->expected_ioctls;
- if ((uffdio_register.ioctls & expected_ioctls) != expected_ioctls)
- err("unexpected missing ioctl for anon memory");
+ assert_expected_ioctls_present(
+ uffdio_register.mode, uffdio_register.ioctls);
if (uffdio_zeropage(uffd, 0))
if (my_bcmp(area_dst, zeropage, page_size))
@@ -1086,7 +1110,6 @@ static int userfaultfd_zeropage_test(void)
static int userfaultfd_events_test(void)
{
struct uffdio_register uffdio_register;
- unsigned long expected_ioctls;
pthread_t uffd_mon;
int err;
pid_t pid;
@@ -1109,9 +1132,8 @@ static int userfaultfd_events_test(void)
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
err("register failure");
- expected_ioctls = uffd_test_ops->expected_ioctls;
- if ((uffdio_register.ioctls & expected_ioctls) != expected_ioctls)
- err("unexpected missing ioctl for anon memory");
+ assert_expected_ioctls_present(
+ uffdio_register.mode, uffdio_register.ioctls);
if (pthread_create(&uffd_mon, &attr, uffd_poll_thread, &stats))
err("uffd_poll_thread create");
@@ -1139,7 +1161,6 @@ static int userfaultfd_events_test(void)
static int userfaultfd_sig_test(void)
{
struct uffdio_register uffdio_register;
- unsigned long expected_ioctls;
unsigned long userfaults;
pthread_t uffd_mon;
int err;
@@ -1163,9 +1184,8 @@ static int userfaultfd_sig_test(void)
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
err("register failure");
- expected_ioctls = uffd_test_ops->expected_ioctls;
- if ((uffdio_register.ioctls & expected_ioctls) != expected_ioctls)
- err("unexpected missing ioctl for anon memory");
+ assert_expected_ioctls_present(
+ uffdio_register.mode, uffdio_register.ioctls);
if (faulting_process(1))
err("faulting process failed");
@@ -1200,30 +1220,25 @@ static int userfaultfd_sig_test(void)
static int userfaultfd_minor_test(void)
{
struct uffdio_register uffdio_register;
- unsigned long expected_ioctls;
unsigned long p;
pthread_t uffd_mon;
uint8_t expected_byte;
void *expected_page;
char c;
struct uffd_stats stats = { 0 };
- uint64_t features;
+ uint64_t features = uffd_minor_feature();
printf("testing minor faults: ");
fflush(stdout);
- if (test_type == TEST_HUGETLB && map_shared)
- features = UFFD_FEATURE_MINOR_HUGETLBFS;
- else if (test_type == TEST_SHMEM)
- features = UFFD_FEATURE_MINOR_SHMEM;
- else {
+ if (!features) {
printf("skipping test due to unsupported memory type\n");
+ fflush(stdout);
return 0;
}
uffd_test_ctx_init(features);
- /* If kernel reports required features aren't supported, skip test. */
- if ((uffd_features & features) != features) {
+ if (!uffd_minor_supported()) {
printf("skipping test due to lack of feature support\n");
fflush(stdout);
return 0;
@@ -1235,10 +1250,8 @@ static int userfaultfd_minor_test(void)
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
err("register failure");
- expected_ioctls = uffd_test_ops->expected_ioctls;
- expected_ioctls |= 1 << _UFFDIO_CONTINUE;
- if ((uffdio_register.ioctls & expected_ioctls) != expected_ioctls)
- err("unexpected missing ioctl(s)");
+ assert_expected_ioctls_present(
+ uffdio_register.mode, uffdio_register.ioctls);
/*
* After registering with UFFD, populate the non-UFFD-registered side of
@@ -1436,8 +1449,6 @@ static int userfaultfd_stress(void)
pthread_attr_setstacksize(&attr, 16*1024*1024);
while (bounces--) {
- unsigned long expected_ioctls;
-
printf("bounces: %d, mode:", bounces);
if (bounces & BOUNCE_RANDOM)
printf(" rnd");
@@ -1465,10 +1476,8 @@ static int userfaultfd_stress(void)
uffdio_register.mode |= UFFDIO_REGISTER_MODE_WP;
if (ioctl(uffd, UFFDIO_REGISTER, &uffdio_register))
err("register failure");
- expected_ioctls = uffd_test_ops->expected_ioctls;
- if ((uffdio_register.ioctls & expected_ioctls) !=
- expected_ioctls)
- err("unexpected missing ioctl for anon memory");
+ assert_expected_ioctls_present(
+ uffdio_register.mode, uffdio_register.ioctls);
if (area_dst_alias) {
uffdio_register.range.start = (unsigned long)
--
2.33.0.464.g1972c5931b-goog
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