[igt-dev] [PATCH i-g-t] tests/gem_userptr_blits: Rework userptr tests to copy with changes

[Maarten Lankhorst]

Userptr semantics are changed to no longer allow forked processes
to obtain pages, it will fail with -EFAULT. We also no longer
allow unsynchronized access, so has_userptr needs to check with the
notifier installed.

The only way to make forked tests work would be to do use a fork
without clone_vm set, which we have no igt infrastructure for,
and can't work like the current igt_fork().

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 tests/i915/gem_userptr_blits.c | 64 +++++++++++++++++++++++++---------
 1 file changed, 48 insertions(+), 16 deletions(-)

diff --git a/tests/i915/gem_userptr_blits.c b/tests/i915/gem_userptr_blits.c
index 268423dcd1ed..313579b5253a 100644
--- a/tests/i915/gem_userptr_blits.c
+++ b/tests/i915/gem_userptr_blits.c
@@ -71,7 +71,7 @@
 #define PAGE_SIZE 4096
 #endif
 
-static uint32_t userptr_flags = I915_USERPTR_UNSYNCHRONIZED;
+static uint32_t userptr_flags = 0;
 
 static bool *can_mmap;
 
@@ -504,14 +504,10 @@ static int has_userptr(int fd)
 {
 	uint32_t handle = 0;
 	void *ptr;
-	uint32_t oldflags;
 	int ret;
 
 	igt_assert(posix_memalign(&ptr, PAGE_SIZE, PAGE_SIZE) == 0);
-	oldflags = userptr_flags;
-	gem_userptr_test_unsynchronized();
 	ret = __gem_userptr(fd, ptr, PAGE_SIZE, 0, userptr_flags, &handle);
-	userptr_flags = oldflags;
 	if (ret != 0) {
 		free(ptr);
 		return 0;
@@ -703,10 +699,9 @@ static void test_forked_access(int fd)
 	void *ptr1 = NULL, *ptr2 = NULL;
 	int ret;
 
-	ret = posix_memalign(&ptr1, PAGE_SIZE, sizeof(linear));
-#ifdef MADV_DONTFORK
-	ret |= madvise(ptr1, sizeof(linear), MADV_DONTFORK);
-#endif
+	ptr1 = mmap(NULL, sizeof(linear), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	igt_assert(ptr1 != MAP_FAILED);
+
 	gem_userptr(fd, ptr1, sizeof(linear), 0, userptr_flags, &handle1);
 	igt_assert(ptr1);
 	igt_assert(handle1);
@@ -722,8 +717,17 @@ static void test_forked_access(int fd)
 	memset(ptr1, 0x1, sizeof(linear));
 	memset(ptr2, 0x2, sizeof(linear));
 
-	igt_fork(child, 1)
-		igt_assert_eq(copy(fd, handle1, handle2), 0);
+	igt_fork(child, 1) {
+		ret = copy(fd, handle1, handle2);
+		if (ret) {
+			/*
+			 * userptr being exportable is a misfeature,
+			 * and has now been disallowed
+			 */
+			igt_assert_eq(ret, -EFAULT);
+			memset(ptr1, 0x2, sizeof(linear));
+		}
+	}
 	igt_waitchildren();
 
 	gem_userptr_sync(fd, handle1);
@@ -734,11 +738,7 @@ static void test_forked_access(int fd)
 
 	igt_assert(memcmp(ptr1, ptr2, sizeof(linear)) == 0);
 
-#ifdef MADV_DOFORK
-	ret = madvise(ptr1, sizeof(linear), MADV_DOFORK);
-	igt_assert_eq(ret, 0);
-#endif
-	free(ptr1);
+	munmap(ptr1, sizeof(linear));
 
 #ifdef MADV_DOFORK
 	ret = madvise(ptr2, sizeof(linear), MADV_DOFORK);
@@ -1615,12 +1615,44 @@ static int can_swap(void)
 	return 1;
 }
 
+static bool forked_userptr(int fd)
+{
+	uint32_t handle = 0;
+	int *ptr = NULL;
+	int ret;
+
+	ptr = mmap(NULL, sizeof(linear), PROT_READ | PROT_WRITE, MAP_SHARED | MAP_ANONYMOUS, -1, 0);
+	igt_assert(ptr != MAP_FAILED);
+
+	*ptr = -1;
+
+	gem_userptr(fd, linear, sizeof(linear), 0, userptr_flags, &handle);
+	igt_assert(handle);
+
+	igt_fork(child, 1)
+		*ptr = copy(fd, handle, handle);
+
+	igt_waitchildren();
+	ret = *ptr;
+
+	gem_close(fd, handle);
+
+	munmap(ptr, sizeof(linear));
+
+	if (ret)
+		igt_assert_eq(ret, -EFAULT);
+
+	return !ret;
+}
+
 static void test_forking_evictions(int fd, int size, int count,
 			     unsigned flags)
 {
 	int trash_count;
 	int num_threads;
 
+	igt_require(forked_userptr(fd));
+
 	trash_count = intel_get_total_ram_mb() * 11 / 10;
 	/* Use the fact test will spawn a number of child
 	 * processes meaning swapping will be triggered system
-- 
2.28.0