Check if the OS has an MMU. If not, then skip tests that only work for systems that have an MMU. The safest and most generic method I found is the FIONBIO ioctl that is available for any file descriptor and is a write-only ioctl, so no memory will be accidentally written. On a MMU system this will return EFAULT, and on a ucLinux system this will return 0. Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx> --- Dillon, the original RFC patch (1) I posted to fix this in the kernel is not the correct method. See: https://stackoverflow.com/questions/24755103/how-to-handle-null-pointer-argument-to-ioctl-system-call So instead I try to detect if there is an MMU in v4l2-compliance and, if not, just skip those tests that require an MMU. Can you test this patch? Thanks! Hans 1: https://patchwork.linuxtv.org/project/linux-media/patch/3acd9ee4-5a58-6ed4-17fe-61596a5252b8@xxxxxxxxx/ --- diff --git a/utils/v4l2-compliance/v4l2-compliance.cpp b/utils/v4l2-compliance/v4l2-compliance.cpp index 0eeabb2d..c53a55ba 100644 --- a/utils/v4l2-compliance/v4l2-compliance.cpp +++ b/utils/v4l2-compliance/v4l2-compliance.cpp @@ -88,6 +88,7 @@ bool is_vivid; bool is_uvcvideo; int media_fd = -1; unsigned warnings; +bool has_mmu = true; static unsigned color_component; static unsigned color_skip; @@ -152,8 +153,21 @@ static struct option long_options[] = { static void print_sha() { + int fd = open("/dev/null", O_RDONLY); + + if (fd >= 0) { + // FIONBIO is a write-only ioctl that takes an int argument that + // enables (!= 0) or disables (== 0) nonblocking mode of a fd. + // + // Passing a nullptr should return EFAULT on MMU capable machines, + // and it works if there is no MMU. + has_mmu = ioctl(fd, FIONBIO, nullptr); + close(fd); + } printf("v4l2-compliance %s%s, ", PACKAGE_VERSION, STRING(GIT_COMMIT_CNT)); - printf("%zd bits, %zd-bit time_t\n", sizeof(void *) * 8, sizeof(time_t) * 8); + printf("%zd bits, %zd-bit time_t%s\n", + sizeof(void *) * 8, sizeof(time_t) * 8, + has_mmu ? "" : ", has no MMU"); if (strlen(STRING(GIT_SHA))) printf("v4l2-compliance SHA: %s %s\n", STRING(GIT_SHA), STRING(GIT_COMMIT_DATE)); @@ -623,9 +637,9 @@ static int testCap(struct node *node) V4L2_CAP_VIDEO_M2M; memset(&vcap, 0xff, sizeof(vcap)); - // Must always be there - fail_on_test(doioctl(node, VIDIOC_QUERYCAP, nullptr) != EFAULT); fail_on_test(doioctl(node, VIDIOC_QUERYCAP, &vcap)); + if (has_mmu) + fail_on_test(doioctl(node, VIDIOC_QUERYCAP, nullptr) != EFAULT); fail_on_test(check_ustring(vcap.driver, sizeof(vcap.driver))); fail_on_test(check_ustring(vcap.card, sizeof(vcap.card))); fail_on_test(check_ustring(vcap.bus_info, sizeof(vcap.bus_info))); @@ -988,11 +1002,10 @@ void testNode(struct node &node, struct node &node_m2m_cap, struct node &expbuf_ } if (driver.empty()) - printf("Compliance test for device %s%s:\n\n", - node.device, node.g_direct() ? "" : " (using libv4l2)"); + printf("Compliance test for device "); else - printf("Compliance test for %s device %s%s:\n\n", - driver.c_str(), node.device, node.g_direct() ? "" : " (using libv4l2)"); + printf("Compliance test for %s device ", driver.c_str()); + printf("%s%s:\n\n", node.device, node.g_direct() ? "" : " (using libv4l2)"); if (node.g_caps() & (V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VBI_CAPTURE | V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_SLICED_VBI_CAPTURE | diff --git a/utils/v4l2-compliance/v4l2-compliance.h b/utils/v4l2-compliance/v4l2-compliance.h index e73ebdd3..7255161f 100644 --- a/utils/v4l2-compliance/v4l2-compliance.h +++ b/utils/v4l2-compliance/v4l2-compliance.h @@ -58,6 +58,7 @@ extern bool is_uvcvideo; // We're testing the uvc driver extern int kernel_version; extern int media_fd; extern unsigned warnings; +extern bool has_mmu; enum poll_mode { POLL_MODE_NONE, diff --git a/utils/v4l2-compliance/v4l2-test-io-config.cpp b/utils/v4l2-compliance/v4l2-test-io-config.cpp index 6f2a9ba9..dcab40b8 100644 --- a/utils/v4l2-compliance/v4l2-test-io-config.cpp +++ b/utils/v4l2-compliance/v4l2-test-io-config.cpp @@ -577,6 +577,8 @@ static int checkEdid(struct node *node, unsigned pad, bool is_input) fail_on_test(edid.blocks == 0 || edid.blocks >= 256); fail_on_test(edid.pad != pad); } + if (!has_mmu) + return 0; edid.blocks = 1; edid.pad = pad; edid.edid = nullptr; diff --git a/utils/v4l2-compliance/v4l2-test-media.cpp b/utils/v4l2-compliance/v4l2-test-media.cpp index ef2982c0..28af0d83 100644 --- a/utils/v4l2-compliance/v4l2-test-media.cpp +++ b/utils/v4l2-compliance/v4l2-test-media.cpp @@ -32,8 +32,9 @@ int testMediaDeviceInfo(struct node *node) struct media_device_info mdinfo; memset(&mdinfo, 0xff, sizeof(mdinfo)); - fail_on_test(doioctl(node, MEDIA_IOC_DEVICE_INFO, nullptr) != EFAULT); fail_on_test(doioctl(node, MEDIA_IOC_DEVICE_INFO, &mdinfo)); + if (has_mmu) + fail_on_test(doioctl(node, MEDIA_IOC_DEVICE_INFO, nullptr) != EFAULT); fail_on_test(check_0(mdinfo.reserved, sizeof(mdinfo.reserved))); fail_on_test(check_string(mdinfo.driver, sizeof(mdinfo.driver))); fail_on_test(mdinfo.model[0] && check_string(mdinfo.model, sizeof(mdinfo.model))); @@ -127,21 +128,23 @@ int testMediaTopology(struct node *node) fail_on_test(topology.reserved2); fail_on_test(topology.reserved3); fail_on_test(topology.reserved4); - topology.ptr_entities = 4; - fail_on_test(doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); - topology.ptr_entities = 0; - topology.ptr_interfaces = 4; - fail_on_test(topology.num_interfaces && - doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); - topology.ptr_interfaces = 0; - topology.ptr_pads = 4; - fail_on_test(topology.num_pads && - doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); - topology.ptr_pads = 0; - topology.ptr_links = 4; - fail_on_test(topology.num_links && - doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); - topology.ptr_links = 0; + if (has_mmu) { + topology.ptr_entities = 4; + fail_on_test(doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); + topology.ptr_entities = 0; + topology.ptr_interfaces = 4; + fail_on_test(topology.num_interfaces && + doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); + topology.ptr_interfaces = 0; + topology.ptr_pads = 4; + fail_on_test(topology.num_pads && + doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); + topology.ptr_pads = 0; + topology.ptr_links = 4; + fail_on_test(topology.num_links && + doioctl(node, MEDIA_IOC_G_TOPOLOGY, &topology) != EFAULT); + topology.ptr_links = 0; + } v2_ents = new media_v2_entity[topology.num_entities]; memset(v2_ents, 0xff, topology.num_entities * sizeof(*v2_ents)); topology.ptr_entities = (uintptr_t)v2_ents; @@ -394,12 +397,14 @@ int testMediaEnum(struct node *node) fail_on_test(links.entity != ent.id); fail_on_test(links.pads); fail_on_test(links.links); - links.pads = (struct media_pad_desc *)4; - fail_on_test(ent.pads && doioctl(node, MEDIA_IOC_ENUM_LINKS, &links) != EFAULT); - links.pads = nullptr; - links.links = (struct media_link_desc *)4; - fail_on_test(ent.links && doioctl(node, MEDIA_IOC_ENUM_LINKS, &links) != EFAULT); - links.links = nullptr; + if (has_mmu) { + links.pads = (struct media_pad_desc *)4; + fail_on_test(ent.pads && doioctl(node, MEDIA_IOC_ENUM_LINKS, &links) != EFAULT); + links.pads = nullptr; + links.links = (struct media_link_desc *)4; + fail_on_test(ent.links && doioctl(node, MEDIA_IOC_ENUM_LINKS, &links) != EFAULT); + links.links = nullptr; + } links.pads = new media_pad_desc[ent.pads]; memset(links.pads, 0xff, ent.pads * sizeof(*links.pads)); links.links = new media_link_desc[ent.links]; diff --git a/utils/v4l2-compliance/v4l2-test-subdevs.cpp b/utils/v4l2-compliance/v4l2-test-subdevs.cpp index 68f97205..f3d85771 100644 --- a/utils/v4l2-compliance/v4l2-test-subdevs.cpp +++ b/utils/v4l2-compliance/v4l2-test-subdevs.cpp @@ -33,8 +33,9 @@ int testSubDevCap(struct node *node) memset(&caps, 0xff, sizeof(caps)); // Must always be there - fail_on_test(doioctl(node, VIDIOC_SUBDEV_QUERYCAP, nullptr) != EFAULT); fail_on_test(doioctl(node, VIDIOC_SUBDEV_QUERYCAP, &caps)); + if (has_mmu) + fail_on_test(doioctl(node, VIDIOC_SUBDEV_QUERYCAP, nullptr) != EFAULT); fail_on_test(check_0(caps.reserved, sizeof(caps.reserved))); fail_on_test((caps.version >> 16) < 5); fail_on_test(caps.capabilities & ~VALID_SUBDEV_CAPS);
