[igt-dev] [RFC PATCH] tests/gem_userptr_blits: Check for banned mmap-offset

Janusz Krzysztofik janusz.krzysztofik at linux.intel.com
Fri Apr 9 08:57:04 UTC 2021


Support for mmap-offset to userptr has been obsoleted, then related
lockdep splat reported issues are not going to be resolved other than
still banning mmap-offset to userptr attempts.

Replace "mmap-offset-invalidate-*" and "readonly-mmap-unsync" subtests
which now skip with a negative "mmap-offset-banned" that fails if a
mmap-offset attempt to a userptr object doesn't return ENODEV.  Also,
remove mmap-offset to userptr dependent processing paths from other
subtest bodies and drop obsolete subtest variants.

Signed-off-by: Janusz Krzysztofik <janusz.krzysztofik at linux.intel.com>
---
 tests/i915/gem_userptr_blits.c | 324 +++------------------------------
 1 file changed, 30 insertions(+), 294 deletions(-)

diff --git a/tests/i915/gem_userptr_blits.c b/tests/i915/gem_userptr_blits.c
index 7a80c0161..aad5f141b 100644
--- a/tests/i915/gem_userptr_blits.c
+++ b/tests/i915/gem_userptr_blits.c
@@ -70,52 +70,12 @@
 #endif
 
 static uint32_t userptr_flags;
-static bool *can_mmap;
 
 #define WIDTH 512
 #define HEIGHT 512
 
 static uint32_t linear[WIDTH*HEIGHT];
 
-static bool has_mmap(int i915, const struct mmap_offset *t)
-{
-	void *ptr, *map;
-	uint32_t handle;
-
-	handle = gem_create(i915, PAGE_SIZE);
-	map = __gem_mmap_offset(i915, handle, 0, PAGE_SIZE, PROT_WRITE,
-				t->type);
-	gem_close(i915, handle);
-	if (map) {
-		munmap(map, PAGE_SIZE);
-	} else {
-		igt_debug("no HW / kernel support for mmap-offset(%s)\n",
-			  t->name);
-		return false;
-	}
-	map = NULL;
-
-	igt_assert(posix_memalign(&ptr, PAGE_SIZE, PAGE_SIZE) == 0);
-
-	if (__gem_userptr(i915, ptr, 4096, 0,
-			  I915_USERPTR_UNSYNCHRONIZED, &handle))
-		goto out_ptr;
-	igt_assert(handle != 0);
-
-	map = __gem_mmap_offset(i915, handle, 0, 4096, PROT_WRITE, t->type);
-	if (map)
-		munmap(map, 4096);
-	else
-		igt_debug("mmap-offset(%s) banned, lockdep loop prevention\n",
-			  t->name);
-
-	gem_close(i915, handle);
-out_ptr:
-	free(ptr);
-
-	return map != NULL;
-}
-
 static void gem_userptr_test_unsynchronized(void)
 {
 	userptr_flags = I915_USERPTR_UNSYNCHRONIZED;
@@ -914,28 +874,13 @@ static int test_invalid_mapping(int fd, const struct mmap_offset *t)
 }
 
 #define PE_BUSY 0x1
-static void test_process_exit(int fd, const struct mmap_offset *mmo, int flags)
+static void test_process_exit(int fd, int flags)
 {
-	if (mmo)
-		igt_require_f(can_mmap[mmo->type],
-			      "HW & kernel support for LLC and mmap-offset(%s) over userptr\n",
-			      mmo->name);
-
 	igt_fork(child, 1) {
 		uint32_t handle;
 
 		handle = create_userptr_bo(fd, sizeof(linear));
 
-		if (mmo) {
-			uint32_t *ptr;
-
-			ptr = __gem_mmap_offset(fd, handle, 0, sizeof(linear),
-						PROT_READ | PROT_WRITE,
-						mmo->type);
-			if (ptr)
-				*ptr = 0;
-		}
-
 		if (flags & PE_BUSY)
 			igt_assert_eq(copy(fd, handle, handle), 0);
 	}
@@ -1064,53 +1009,30 @@ static int test_map_fixed_invalidate(int fd, uint32_t flags,
 	return 0;
 }
 
-static void test_mmap_offset_invalidate(int fd,
-					const struct mmap_offset *t,
-					unsigned int flags)
-#define MMOI_ACTIVE (1u << 0)
+static void test_mmap_offset_banned(int fd, const struct mmap_offset *t)
 {
-	igt_spin_t *spin = NULL;
-	uint32_t handle;
-	uint32_t *map;
+	struct drm_i915_gem_mmap_offset arg;
 	void *ptr;
 
 	/* check if mmap_offset type is supported by hardware, skip if not */
-	handle = gem_create(fd, PAGE_SIZE);
-	map = __gem_mmap_offset(fd, handle, 0, PAGE_SIZE,
-				PROT_READ | PROT_WRITE, t->type);
-	igt_require_f(map,
-		      "HW & kernel support for mmap_offset(%s)\n", t->name);
-	munmap(map, PAGE_SIZE);
-	gem_close(fd, handle);
+	memset(&arg, 0, sizeof(arg));
+	arg.flags = t->type;
+	arg.handle = gem_create(fd, PAGE_SIZE);
+	igt_skip_on_f(igt_ioctl(fd, DRM_IOCTL_I915_GEM_MMAP_OFFSET, &arg),
+				"HW & kernel support for mmap_offset(%s)\n", t->name);
+	gem_close(fd, arg.handle);
 
 	/* create userptr object */
+	memset(&arg, 0, sizeof(arg));
+	arg.flags = t->type;
 	igt_assert_eq(posix_memalign(&ptr, PAGE_SIZE, PAGE_SIZE), 0);
-	gem_userptr(fd, ptr, PAGE_SIZE, 0, userptr_flags, &handle);
+	gem_userptr(fd, ptr, PAGE_SIZE, 0, userptr_flags, &arg.handle);
 
-	/* set up mmap-offset mapping on top of the object, skip if refused */
-	map = __gem_mmap_offset(fd, handle, 0, PAGE_SIZE,
-				PROT_READ | PROT_WRITE, t->type);
-	igt_require_f(map, "mmap-offset banned, lockdep loop prevention\n");
-
-	/* set object pages in order to activate MMU notifier for it */
-	gem_set_domain(fd, handle, t->domain, t->domain);
-	*map = 0;
-
-	if (flags & MMOI_ACTIVE) {
-		gem_quiescent_gpu(fd);
-		spin = igt_spin_new(fd,
-				    .dependency = handle,
-				    .flags = IGT_SPIN_NO_PREEMPTION);
-		igt_spin_set_timeout(spin, NSEC_PER_SEC); /* XXX borked */
-	}
+	/* try to set up mmap-offset mapping on top of the object, fail if not banned */
+	do_ioctl_err(fd, DRM_IOCTL_I915_GEM_MMAP_OFFSET, &arg, ENODEV);
 
-	/* trigger the notifier */
+	gem_close(fd, arg.handle);
 	munmap(ptr, PAGE_SIZE);
-
-	/* cleanup */
-	igt_spin_free(fd, spin);
-	munmap(map, PAGE_SIZE);
-	gem_close(fd, handle);
 }
 
 static int test_forbidden_ops(int fd)
@@ -1195,36 +1117,28 @@ static void (* volatile orig_sigbus)(int sig, siginfo_t *info, void *param);
 static volatile unsigned long sigbus_start;
 static volatile long sigbus_cnt = -1;
 
-static void *umap(int fd, uint32_t handle, const struct mmap_offset *mmo)
+static void *umap(int fd, uint32_t handle)
 {
 	void *ptr;
+	uint32_t tmp = gem_create(fd, sizeof(linear));
 
-	if (mmo) {
-		ptr = __gem_mmap_offset(fd, handle, 0, sizeof(linear),
-					PROT_READ | PROT_WRITE, mmo->type);
-		igt_assert(ptr);
-	} else {
-		uint32_t tmp = gem_create(fd, sizeof(linear));
-		igt_assert_eq(copy(fd, tmp, handle), 0);
-		ptr = gem_mmap__cpu(fd, tmp, 0, sizeof(linear), PROT_READ);
-		gem_close(fd, tmp);
-	}
+	igt_assert_eq(copy(fd, tmp, handle), 0);
+	ptr = gem_mmap__cpu(fd, tmp, 0, sizeof(linear), PROT_READ);
+	gem_close(fd, tmp);
 
 	return ptr;
 }
 
 static void
-check_bo(int fd1, uint32_t handle1, int is_userptr, int fd2, uint32_t handle2,
-	 const struct mmap_offset *mmo)
+check_bo(int fd1, uint32_t handle1, int is_userptr, int fd2, uint32_t handle2)
 {
 	unsigned char *ptr1, *ptr2;
-	unsigned long size = sizeof(linear);
 
-	ptr2 = umap(fd2, handle2, mmo);
+	ptr2 = umap(fd2, handle2);
 	if (is_userptr)
 		ptr1 = is_userptr > 0 ? get_handle_ptr(handle1) : ptr2;
 	else
-		ptr1 = umap(fd1, handle1, mmo);
+		ptr1 = umap(fd1, handle1);
 
 	igt_assert(ptr1);
 	igt_assert(ptr2);
@@ -1232,12 +1146,6 @@ check_bo(int fd1, uint32_t handle1, int is_userptr, int fd2, uint32_t handle2,
 	sigbus_start = (unsigned long)ptr2;
 	igt_assert(memcmp(ptr1, ptr2, sizeof(linear)) == 0);
 
-	if (mmo) {
-		counter++;
-		memset(ptr1, counter, size);
-		memset(ptr2, counter, size);
-	}
-
 	if (!is_userptr)
 		munmap(ptr1, sizeof(linear));
 	munmap(ptr2, sizeof(linear));
@@ -1260,47 +1168,15 @@ static int export_handle(int fd, uint32_t handle, int *outfd)
 	return ret;
 }
 
-static void sigbus(int sig, siginfo_t *info, void *param)
-{
-	unsigned long ptr = (unsigned long)info->si_addr;
-	void *addr;
-
-	if (ptr >= sigbus_start &&
-	    ptr < sigbus_start + sizeof(linear)) {
-		/* replace mapping to allow progress */
-		munmap((void *)sigbus_start, sizeof(linear));
-		addr = mmap((void *)sigbus_start, sizeof(linear),
-			    PROT_READ | PROT_WRITE,
-			    MAP_ANONYMOUS | MAP_PRIVATE | MAP_FIXED, -1, 0);
-		igt_assert((unsigned long)addr == sigbus_start);
-		memset(addr, counter, sizeof(linear));
-
-		sigbus_cnt++;
-		return;
-	}
-
-	if (orig_sigbus)
-		orig_sigbus(sig, info, param);
-	igt_assert(0);
-}
-
 static int test_dmabuf(void)
 {
 	int fd1, fd2;
 	uint32_t handle, handle_import;
 	int dma_buf_fd = -1;
 	int ret;
-	const struct mmap_offset *mmo = NULL;
 
 	fd1 = drm_open_driver(DRIVER_INTEL);
 
-	for_each_mmap_offset_type(fd1, t)
-		if (can_mmap[t->type]) {
-			igt_debug("using mmap-offset(%s)\n", t->name);
-			mmo = t;
-			break;
-	}
-
 	handle = create_userptr_bo(fd1, sizeof(linear));
 	memset(get_handle_ptr(handle), counter, sizeof(linear));
 
@@ -1317,35 +1193,16 @@ static int test_dmabuf(void)
 
 	fd2 = drm_open_driver(DRIVER_INTEL);
 	handle_import = prime_fd_to_handle(fd2, dma_buf_fd);
-	check_bo(fd1, handle, 1, fd2, handle_import, mmo);
+	check_bo(fd1, handle, 1, fd2, handle_import);
 
 	/* close dma_buf, check whether nothing disappears. */
 	close(dma_buf_fd);
-	check_bo(fd1, handle, 1, fd2, handle_import, mmo);
+	check_bo(fd1, handle, 1, fd2, handle_import);
 
 	/* destroy userptr object and expect SIGBUS */
 	free_userptr_bo(fd1, handle);
 	close(fd1);
 
-	if (mmo) {
-		struct sigaction sigact, orig_sigact;
-
-		memset(&sigact, 0, sizeof(sigact));
-		sigact.sa_sigaction = sigbus;
-		sigact.sa_flags = SA_SIGINFO;
-		ret = sigaction(SIGBUS, &sigact, &orig_sigact);
-		igt_assert_eq(ret, 0);
-
-		orig_sigbus = orig_sigact.sa_sigaction;
-
-		sigbus_cnt = 0;
-		check_bo(fd2, handle_import, -1, fd2, handle_import, mmo);
-		igt_assert(sigbus_cnt > 0);
-
-		ret = sigaction(SIGBUS, &orig_sigact, NULL);
-		igt_assert_eq(ret, 0);
-	}
-
 	close(fd2);
 	reset_handle_ptr();
 
@@ -1548,93 +1405,6 @@ static void test_readonly(int i915)
 	munmap(pages, sz);
 }
 
-static jmp_buf sigjmp;
-
-__noreturn static void sigjmp_handler(int sig)
-{
-	siglongjmp(sigjmp, sig);
-}
-
-static void test_readonly_mmap(int i915, const struct mmap_offset *t)
-{
-	char *original, *result;
-	uint32_t handle;
-	uint32_t sz;
-	void *pages;
-	void *ptr;
-	int sig;
-
-	/*
-	 * A quick check to ensure that we cannot circumvent the
-	 * read-only nature of our memory by creating a GTT mmap into
-	 * the pages. Imagine receiving a readonly SHM segment from
-	 * another process, or a readonly file mmap, it must remain readonly
-	 * on the GPU as well.
-	 */
-
-	handle = gem_create(i915, PAGE_SIZE);
-	ptr = __gem_mmap_offset(i915, handle, 0, PAGE_SIZE,
-				PROT_READ | PROT_WRITE, t->type);
-	gem_close(i915, handle);
-	igt_require_f(ptr, "HW & kernel support for mmap-offset(%s)\n",
-		      t->name);
-	munmap(ptr, PAGE_SIZE);
-
-	igt_require(igt_setup_clflush());
-
-	sz = 16 << 12;
-	pages = mmap(NULL, sz, PROT_WRITE, MAP_ANON | MAP_PRIVATE, -1, 0);
-	igt_assert(pages != MAP_FAILED);
-
-	igt_require(__gem_userptr(i915, pages, sz, true, userptr_flags, &handle) == 0);
-	gem_set_caching(i915, handle, 0);
-
-	memset(pages, 0xa5, sz);
-	igt_clflush_range(pages, sz);
-	original = g_compute_checksum_for_data(G_CHECKSUM_SHA1, pages, sz);
-
-	ptr = __gem_mmap_offset(i915, handle, 0, sz, PROT_WRITE, t->type);
-	igt_assert(ptr == NULL);
-
-	/* Optional kernel support for GTT mmaps of userptr */
-	ptr = __gem_mmap_offset(i915, handle, 0, sz, PROT_READ, t->type);
-	gem_close(i915, handle);
-
-	if (ptr) { /* Check that a write into the GTT readonly map fails */
-		if (!(sig = sigsetjmp(sigjmp, 1))) {
-			signal(SIGBUS, sigjmp_handler);
-			signal(SIGSEGV, sigjmp_handler);
-			memset(ptr, 0x5a, sz);
-			igt_assert(0);
-		}
-		igt_assert_eq(sig, SIGSEGV);
-
-		/* Check that we disallow removing the readonly protection */
-		igt_assert(mprotect(ptr, sz, PROT_WRITE));
-		if (!(sig = sigsetjmp(sigjmp, 1))) {
-			signal(SIGBUS, sigjmp_handler);
-			signal(SIGSEGV, sigjmp_handler);
-			memset(ptr, 0x5a, sz);
-			igt_assert(0);
-		}
-		igt_assert_eq(sig, SIGSEGV);
-
-		/* A single read from the GTT pointer to prove that works */
-		igt_assert_eq_u32(*(uint8_t *)ptr, 0xa5);
-		munmap(ptr, sz);
-	}
-
-	/* Double check that the kernel did indeed not let any writes through */
-	igt_clflush_range(pages, sz);
-	result = g_compute_checksum_for_data(G_CHECKSUM_SHA1, pages, sz);
-	igt_assert(!strcmp(original, result));
-
-	g_free(original);
-	g_free(result);
-
-	munmap(pages, sz);
-}
-
 static void test_readonly_pwrite(int i915)
 {
 	char *original, *result;
@@ -2423,12 +2193,6 @@ igt_main_args("c:", NULL, help_str, opt_handler, NULL)
 				mmo_max = t->type + 1;
 		igt_assert(mmo_max);
 
-		can_mmap = calloc(mmo_max, sizeof(*can_mmap));
-		igt_assert(can_mmap);
-
-		for_each_mmap_offset_type(fd, t)
-			can_mmap[t->type] = has_mmap(fd, t) && gem_has_llc(fd);
-
 		size = sizeof(linear);
 
 		aperture_size = gem_aperture_size(fd);
@@ -2520,12 +2284,6 @@ igt_main_args("c:", NULL, help_str, opt_handler, NULL)
 		igt_subtest("readonly-unsync")
 			test_readonly(fd);
 
-		igt_describe("Examine mmap-offset mapping to read-only userptr");
-		igt_subtest_with_dynamic("readonly-mmap-unsync")
-			for_each_mmap_offset_type(fd, t)
-				igt_dynamic(t->name)
-					test_readonly_mmap(fd, t);
-
 		igt_subtest("readonly-pwrite-unsync")
 			test_readonly_pwrite(fd);
 
@@ -2595,22 +2353,10 @@ igt_main_args("c:", NULL, help_str, opt_handler, NULL)
 		}
 
 		igt_subtest("process-exit")
-			test_process_exit(fd, NULL, 0);
-
-		igt_describe("Test process exit with userptr object mmapped via mmap-offset");
-		igt_subtest_with_dynamic("process-exit-mmap")
-			for_each_mmap_offset_type(fd, t)
-				igt_dynamic(t->name)
-					test_process_exit(fd, t, 0);
+			test_process_exit(fd, 0);
 
 		igt_subtest("process-exit-busy")
-			test_process_exit(fd, NULL, PE_BUSY);
-
-		igt_describe("Test process exit with busy userptr object mmapped via mmap-offset");
-		igt_subtest_with_dynamic("process-exit-mmap-busy")
-			for_each_mmap_offset_type(fd, t)
-				igt_dynamic(t->name)
-					test_process_exit(fd, t, PE_BUSY);
+			test_process_exit(fd, PE_BUSY);
 
 		igt_subtest("create-destroy-sync")
 			test_create_destroy(fd, 5);
@@ -2655,18 +2401,11 @@ igt_main_args("c:", NULL, help_str, opt_handler, NULL)
 			}
 		}
 
-		igt_describe("Invalidate pages of idle userptr with mmap-offset on top");
-		igt_subtest_with_dynamic("mmap-offset-invalidate-idle")
+		igt_describe("Verify mmap_offset to userptr is banned");
+		igt_subtest_with_dynamic("mmap-offset-banned")
 			for_each_mmap_offset_type(fd, t)
 				igt_dynamic_f("%s", t->name)
-					test_mmap_offset_invalidate(fd, t, 0);
-
-		igt_describe("Invalidate pages of active userptr with mmap-offset on top");
-		igt_subtest_with_dynamic("mmap-offset-invalidate-active")
-			for_each_mmap_offset_type(fd, t)
-				igt_dynamic_f("%s", t->name)
-					test_mmap_offset_invalidate(fd, t,
-								   MMOI_ACTIVE);
+					test_mmap_offset_banned(fd, t);
 
 		igt_subtest("coherency-sync")
 			test_coherency(fd, count);
@@ -2748,7 +2487,4 @@ igt_main_args("c:", NULL, help_str, opt_handler, NULL)
 
 	igt_subtest("access-control")
 		test_access_control(fd);
-
-	igt_fixture
-		free(can_mmap);
 }
-- 
2.25.1



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