From 0aaa69e4d73fb5ecc7f2eb2d2a2d84804704b962 Mon Sep 17 00:00:00 2001 From: ReinUsesLisp Date: Wed, 26 Feb 2020 16:51:53 -0300 Subject: vk_swapchain: Silence TOCTOU race condition It's possible that the window is resized from the moment we ask for its size to the moment a swapchain is created, causing validation issues. To workaround this Vulkan issue request the capabilities again just before creating the swapchain, making the race condition less likely. --- src/video_core/renderer_vulkan/vk_swapchain.cpp | 21 ++++++++++++--------- 1 file changed, 12 insertions(+), 9 deletions(-) (limited to 'src/video_core/renderer_vulkan') diff --git a/src/video_core/renderer_vulkan/vk_swapchain.cpp b/src/video_core/renderer_vulkan/vk_swapchain.cpp index f47b691a8..9e73fa9cd 100644 --- a/src/video_core/renderer_vulkan/vk_swapchain.cpp +++ b/src/video_core/renderer_vulkan/vk_swapchain.cpp @@ -141,11 +141,6 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities const vk::SurfaceFormatKHR surface_format{ChooseSwapSurfaceFormat(formats, srgb)}; 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}; if (capabilities.maxImageCount > 0 && requested_image_count > capabilities.maxImageCount) { @@ -153,10 +148,9 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities } vk::SwapchainCreateInfoKHR swapchain_ci( - {}, surface, requested_image_count, surface_format.format, surface_format.colorSpace, - extent, 1, vk::ImageUsageFlagBits::eColorAttachment, {}, {}, {}, - capabilities.currentTransform, vk::CompositeAlphaFlagBitsKHR::eOpaque, present_mode, false, - {}); + {}, surface, requested_image_count, surface_format.format, surface_format.colorSpace, {}, 1, + vk::ImageUsageFlagBits::eColorAttachment, {}, {}, {}, capabilities.currentTransform, + vk::CompositeAlphaFlagBitsKHR::eOpaque, present_mode, false, {}); const u32 graphics_family{device.GetGraphicsFamily()}; const u32 present_family{device.GetPresentFamily()}; @@ -169,9 +163,18 @@ void VKSwapchain::CreateSwapchain(const vk::SurfaceCapabilitiesKHR& capabilities 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()}; 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); image_count = static_cast(images.size()); image_format = surface_format.format; -- cgit v1.2.3