scp-fs2open/fs2open.github.com
1
0 Fork 0
mirror of https://github.com/scp-fs2open/fs2open.github.com.git synced 2026-11-07 08:15:59 -10:00
Code Issues Packages Projects Releases 1 Wiki Activity

Vulkan: reject truncated shader cache files (#7936)

Browse Source 
The runtime shader compiler cached SPIR-V on disk without checking the
write, and accepted any cached file whose size was a multiple of four.
A file cut short by a crash or a full disk was handed to the driver as a
shader module. With half-length cache files in place, master crashes in
the NVIDIA driver on entering SM1-01 under -vulkan.

Cached files are now checked before use: the SPIR-V magic word, and the
instruction word counts must end exactly at the end of the file on an
OpFunctionEnd. A file that fails is logged, recompiled and rewritten.
Fresh compiler output is checked the same way before it is cached, so a
module the check would reject is never written, and the log says so.

New cache files are written to a temporary file unique to the writer and
renamed over the old .spv only after a complete write and close, so a
game crash, or a second game writing the same shader, never leaves a
partial .spv. A power loss still can; the read check catches that.
purgeOldCache now also removes old temporary files.

Co-authored-by: Dustinspace217 <[email protected]>
This commit is contained in:
dustinspace217andDustinspace217 authored and GitHub committed 2026-11-04 18:19:18 +01:00
1 parent c58a0cd307
commit 03589b49bf
1 file changed
+73 -26
Download Patch File Download Diff File Expand all files Collapse all files
code/graphics/vulkan/VulkanShaderCompiler.cpp
+73 -26
View File
@@ -8,6 +8,7 @@
#include "globalincs/systemvars.h"
#include "graphics/post_processing.h"
#include <chrono>
#include <md5.h>
#include <shaderc/shaderc.h>
@@ -214,6 +215,28 @@ SCP_string VulkanShaderCompiler::computeSourceHash(const SCP_string& header, con
return md5.hexdigest();
}
// rejects a cache file cut short by a crash or full disk: a complete module ends exactly on an OpFunctionEnd
static bool isCompleteSpirv(const SCP_vector<uint32_t>& spirv)
{
constexpr uint32_t SPIRV_MAGIC = 0x07230203;
constexpr size_t HEADER_WORDS = 5;
constexpr uint32_t OP_FUNCTION_END = 56;
if (spirv.size() < HEADER_WORDS || spirv[0] != SPIRV_MAGIC) {
return false;
}
size_t i = HEADER_WORDS;
uint32_t lastOpcode = 0;
while (i < spirv.size()) {
const uint32_t wordCount = spirv[i] >> 16;
if (wordCount == 0) {
return false;
}
lastOpcode = spirv[i] & 0xFFFF;
i += wordCount;
}
return i == spirv.size() && lastOpcode == OP_FUNCTION_END;
}
SCP_vector<uint32_t> VulkanShaderCompiler::compile(const SCP_string& filename,
vk::ShaderStageFlagBits stage,
shader_type sdrType,
@@ -249,10 +272,13 @@ SCP_vector<uint32_t> VulkanShaderCompiler::compile(const SCP_string& filename,
if (fileSize > 0 && (fileSize % 4) == 0) {
SCP_vector<uint32_t> spirv(fileSize / 4);
if (cfread(spirv.data(), 1, fileSize, cacheFile) == fileSize) {
cfclose(cacheFile);
nprintf(("vulkan", "VulkanShaderCompiler: Cache hit for %s (flags=0x%x)\n",
filename.c_str(), flags));
return spirv;
if (isCompleteSpirv(spirv)) {
cfclose(cacheFile);
nprintf(("vulkan", "VulkanShaderCompiler: Cache hit for %s (flags=0x%x)\n",
filename.c_str(), flags));
return spirv;
}
mprintf(("VulkanShaderCompiler: Ignoring incomplete cache file %s\n", cacheFilename.c_str()));
}
}
cfclose(cacheFile);
@@ -324,11 +350,29 @@ SCP_vector<uint32_t> VulkanShaderCompiler::compile(const SCP_string& filename,
nprintf(("vulkan", "VulkanShaderCompiler: Compiled %s -> %zu bytes SPIR-V\n",
filename.c_str(), byteLen));
// Save to disk cache
cacheFile = cfopen(cacheFilename.c_str(), "wb", CF_TYPE_CACHE);
if (cacheFile != nullptr) {
cfwrite(spirv.data(), static_cast<int>(spirv.size() * sizeof(uint32_t)), 1, cacheFile);
cfclose(cacheFile);
// each writer renames its own temp file, so a game crash or a second game never leaves a truncated .spv
const SCP_string tmpFilename = "vk_shader-" + hash + "-" +
std::to_string(std::chrono::steady_clock::now().time_since_epoch().count()) +
".tmp";
const bool complete = isCompleteSpirv(spirv);
cacheFile = complete ? cfopen(tmpFilename.c_str(), "wb", CF_TYPE_CACHE) : nullptr;
if (!complete) {
mprintf(("VulkanShaderCompiler: Not caching %s: compiled module fails the cache check\n",
cacheFilename.c_str()));
} else if (cacheFile != nullptr) {
const bool written =
cfwrite(spirv.data(), static_cast<int>(spirv.size() * sizeof(uint32_t)), 1, cacheFile) == 1;
const bool closed = cfclose(cacheFile) == 0;
bool saved = false;
if (written && closed) {
// rename() on Windows fails if the target exists
cf_delete(cacheFilename.c_str(), CF_TYPE_CACHE);
saved = cf_rename(tmpFilename.c_str(), cacheFilename.c_str(), CF_TYPE_CACHE) == CF_RENAME_SUCCESS;
}
if (!saved) {
cf_delete(tmpFilename.c_str(), CF_TYPE_CACHE);
mprintf(("VulkanShaderCompiler: Could not write cache file %s\n", cacheFilename.c_str()));
}
}
}
}
@@ -345,26 +389,29 @@ void VulkanShaderCompiler::purgeOldCache()
const SCP_string PREFIX = "vk_shader-";
const auto TIMEOUT = 2.0 * 30.0 * 24.0 * 60.0 * 60.0; // ~2 months in seconds
SCP_vector<SCP_string> cache_files;
SCP_vector<file_list_info> file_info;
cf_get_file_list(cache_files, CF_TYPE_CACHE, "*.spv", CF_SORT_NONE, &file_info,
CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
Assertion(cache_files.size() == file_info.size(),
"cf_get_file_list returned different sizes for file names and file informations!");
auto now = std::time(nullptr);
for (size_t i = 0; i < cache_files.size(); ++i) {
auto& name = cache_files[i];
for (const char* ext : {".spv", ".tmp"}) {
SCP_vector<SCP_string> cache_files;
SCP_vector<file_list_info> file_info;
const SCP_string filter = SCP_string("*") + ext;
cf_get_file_list(cache_files, CF_TYPE_CACHE, filter.c_str(), CF_SORT_NONE, &file_info,
CF_LOCATION_ROOT_USER | CF_LOCATION_ROOT_GAME | CF_LOCATION_TYPE_ROOT);
if (name.compare(0, PREFIX.size(), PREFIX) != 0) {
continue; // Not our cache file
}
Assertion(cache_files.size() == file_info.size(),
"cf_get_file_list returned different sizes for file names and file informations!");
auto diff = std::difftime(now, file_info[i].write_time);
if (diff > TIMEOUT) {
auto full_name = name + ".spv";
cf_delete(full_name.c_str(), CF_TYPE_CACHE);
for (size_t i = 0; i < cache_files.size(); ++i) {
auto& name = cache_files[i];
if (name.compare(0, PREFIX.size(), PREFIX) != 0) {
continue; // Not our cache file
}
auto diff = std::difftime(now, file_info[i].write_time);
if (diff > TIMEOUT) {
auto full_name = name + ext;
cf_delete(full_name.c_str(), CF_TYPE_CACHE);
}
}
}
}