Merge pull request #3463 from ReinUsesLisp/vk-toctou

vk_swapchain: Silence TOCTOU race condition
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bunnei 2020-03-05 19:38:42 -05:00 committed by GitHub
commit 49eff536d0
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@ -141,11 +141,6 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities
const vk::SurfaceFormatKHR surface_format{ChooseSwapSurfaceFormat(formats, srgb)}; const vk::SurfaceFormatKHR surface_format{ChooseSwapSurfaceFormat(formats, srgb)};
const vk::PresentModeKHR present_mode{ChooseSwapPresentMode(present_modes)}; const vk::PresentModeKHR present_mode{ChooseSwapPresentMode(present_modes)};
extent = ChooseSwapExtent(capabilities, width, height);
current_width = extent.width;
current_height = extent.height;
current_srgb = srgb;
u32 requested_image_count{capabilities.minImageCount + 1}; u32 requested_image_count{capabilities.minImageCount + 1};
if (capabilities.maxImageCount > 0 && requested_image_count > capabilities.maxImageCount) { if (capabilities.maxImageCount > 0 && requested_image_count > capabilities.maxImageCount) {
@ -153,10 +148,9 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities
} }
vk::SwapchainCreateInfoKHR swapchain_ci( vk::SwapchainCreateInfoKHR swapchain_ci(
{}, surface, requested_image_count, surface_format.format, surface_format.colorSpace, {}, surface, requested_image_count, surface_format.format, surface_format.colorSpace, {}, 1,
extent, 1, vk::ImageUsageFlagBits::eColorAttachment, {}, {}, {}, vk::ImageUsageFlagBits::eColorAttachment, {}, {}, {}, capabilities.currentTransform,
capabilities.currentTransform, vk::CompositeAlphaFlagBitsKHR::eOpaque, present_mode, false, vk::CompositeAlphaFlagBitsKHR::eOpaque, present_mode, false, {});
{});
const u32 graphics_family{device.GetGraphicsFamily()}; const u32 graphics_family{device.GetGraphicsFamily()};
const u32 present_family{device.GetPresentFamily()}; const u32 present_family{device.GetPresentFamily()};
@ -169,9 +163,18 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities
swapchain_ci.imageSharingMode = vk::SharingMode::eExclusive; swapchain_ci.imageSharingMode = vk::SharingMode::eExclusive;
} }
// Request the size again to reduce the possibility of a TOCTOU race condition.
const auto updated_capabilities = physical_device.getSurfaceCapabilitiesKHR(surface, dld);
swapchain_ci.imageExtent = ChooseSwapExtent(updated_capabilities, width, height);
// Don't add code within this and the swapchain creation.
const auto dev{device.GetLogical()}; const auto dev{device.GetLogical()};
swapchain = dev.createSwapchainKHRUnique(swapchain_ci, nullptr, dld); swapchain = dev.createSwapchainKHRUnique(swapchain_ci, nullptr, dld);
extent = swapchain_ci.imageExtent;
current_width = extent.width;
current_height = extent.height;
current_srgb = srgb;
images = dev.getSwapchainImagesKHR(*swapchain, dld); images = dev.getSwapchainImagesKHR(*swapchain, dld);
image_count = static_cast<u32>(images.size()); image_count = static_cast<u32>(images.size());
image_format = surface_format.format; image_format = surface_format.format;