Add a GSL hook that allows for importing host-mapped memory onto the GPU

include/adrenotools/driver.h

@@ -19,7 +19,22 @@ extern "C" {
  * @param customDriverName The soname of the custom driver to load. Only used if ADRENOTOOLS_DRIVER_CUSTOM is set in `featureFlags`
  * @param fileRedirectDir The directory which to redirect all file accesses performed by the driver to. Only used if ADRENOTOOLS_DRIVER_FILE_REDIRECT is set in `featureFlags`
  */
-void *adrenotools_open_libvulkan(int dlopenMode, int featureFlags, const char *tmpLibDir, const char *hookLibDir, const char *customDriverDir, const char *customDriverName, const char *fileRedirectDir);
+void *adrenotools_open_libvulkan(int dlopenMode, int featureFlags, const char *tmpLibDir, const char *hookLibDir, const char *customDriverDir, const char *customDriverName, const char *fileRedirectDir, adrenotools_gpu_mapping *nextGpuMapping);
+
+/**
+ * @brief Imports the given CPU mapped memory range into the GSL allocator. The out_mapping should have been passed to adrenotools_open_libvulkan with ADRENOTOOLS_DRIVER_GPU_MAPPING_IMPORT set in `featureFlags`. This should then be followed by a call to vkAllocateMemory with a matching size which will return a VkDeviceMemory view over the input region
+ * @param outMapping Output mapping pointer, the same as was passed to adrenotools_open_libvulkan
+ * @param hostPtr The host pointer to import
+ * @param size The size of the region to import
+ * @return True on success
+ */
+bool adrenotools_import_user_mem(adrenotools_gpu_mapping *outMapping, void *hostPtr, uint64_t size);
+
+/**
+ * @note This function should be called after adrenotools_open_libvulkan and Vulkan driver init to check if the mapping import hook loaded successfully
+ * @return True if the mapping was successfully imported (or initialization succeeded)
+ */
+bool adrenotools_validate_gpu_mapping(adrenotools_gpu_mapping *mapping);
 
 #ifdef __cplusplus
 }

include/adrenotools/priv.h

@@ -3,10 +3,25 @@
 
 #pragma once
 
+#include <stdint.h>
+
 /**
  * @brief Bitfield enum of additional driver features that can be used with adrenotools_open_libvulkan
  */
 enum {
     ADRENOTOOLS_DRIVER_CUSTOM = 1 << 0,
-    ADRENOTOOLS_DRIVER_FILE_REDIRECT = 1 << 1
+    ADRENOTOOLS_DRIVER_FILE_REDIRECT = 1 << 1,
+    ADRENOTOOLS_DRIVER_GPU_MAPPING_IMPORT = 1 << 2,
 };
+
+#define ADRENOTOOLS_GPU_MAPPING_SUCCEEDED_MAGIC 0xDEADBEEF
+
+/**
+ * @brief A replacement GPU memory mapping for use with ADRENOTOOLS_DRIVER_GPU_MAPPING_IMPORT
+ */
+struct adrenotools_gpu_mapping {
+    void *host_ptr;
+    uint64_t gpu_addr; //!< The GPU address of the mapping to import, if mapping import/init succeeds this will be set to ADRENOTOOLS_GPU_MAPPING_SUCCEEDED_MAGIC
+    uint64_t size;
+    uint64_t flags;
+};

src/driver.cpp

@@ -4,14 +4,18 @@
 #include <string>
 #include <string_view>
 #include <sys/stat.h>
+#include <sys/ioctl.h>
 #include <dlfcn.h>
+#include <fcntl.h>
 #include <android/api-level.h>
 #include <android/log.h>
 #include <android_linker_ns.h>
+#include "hook/kgsl.h"
 #include "hook/hook_impl_params.h"
 #include <adrenotools/driver.h>
+#include <unistd.h>
 
-void *adrenotools_open_libvulkan(int dlopenFlags, int featureFlags, const char *tmpLibDir, const char *hookLibDir, const char *customDriverDir, const char *customDriverName, const char *fileRedirectDir) {
+void *adrenotools_open_libvulkan(int dlopenFlags, int featureFlags, const char *tmpLibDir, const char *hookLibDir, const char *customDriverDir, const char *customDriverName, const char *fileRedirectDir, adrenotools_gpu_mapping *nextGpuMapping) {
     // Bail out if linkernsbypass failed to load, this probably means we're on api < 28
     if (!linkernsbypass_load_status())
         return nullptr;
@@ -27,6 +31,9 @@ void *adrenotools_open_libvulkan(int dlopenFlags, int featureFlags, const char *
     if (!(featureFlags & ADRENOTOOLS_DRIVER_CUSTOM) && (customDriverDir || customDriverName))
         return nullptr;
 
+    if (!(featureFlags & ADRENOTOOLS_DRIVER_GPU_MAPPING_IMPORT) && nextGpuMapping)
+        return nullptr;
+
     // Verify that params for enabled features are correct
     struct stat buf{};
 
@@ -64,7 +71,7 @@ void *adrenotools_open_libvulkan(int dlopenFlags, int featureFlags, const char *
     if (!initHookParam)
         return nullptr;
 
-    initHookParam(new HookImplParams(featureFlags, tmpLibDir, hookLibDir, customDriverDir, customDriverName, fileRedirectDir));
+    initHookParam(new HookImplParams(featureFlags, tmpLibDir, hookLibDir, customDriverDir, customDriverName, fileRedirectDir, nextGpuMapping));
 
     // Load the libvulkan hook into the isolated namespace
     if (!linkernsbypass_namespace_dlopen("libmain_hook.so", RTLD_GLOBAL, hookNs))
@@ -72,3 +79,48 @@ void *adrenotools_open_libvulkan(int dlopenFlags, int featureFlags, const char *
 
     return linkernsbypass_namespace_dlopen_unique("/system/lib64/libvulkan.so", tmpLibDir, dlopenFlags, hookNs);
 }
+
+bool adrenotools_import_user_mem(adrenotools_gpu_mapping *outMapping, void *hostPtr, uint64_t size) {
+    kgsl_gpuobj_import_useraddr addr{
+        .virtaddr = reinterpret_cast<uint64_t>(hostPtr),
+    };
+
+    kgsl_gpuobj_import user_mem_import{
+        .priv = reinterpret_cast<uint64_t>(&addr),
+        .priv_len = size,
+        .flags = KGSL_CACHEMODE_WRITEBACK << KGSL_CACHEMODE_SHIFT | KGSL_MEMFLAGS_IOCOHERENT,
+        .type = KGSL_USER_MEM_TYPE_ADDR,
+
+    };
+
+    kgsl_gpuobj_info info{};
+
+    int kgslFd{open("/dev/kgsl-3d0", O_RDWR)};
+    if (kgslFd < 0)
+        return false;
+
+    int ret{ioctl(kgslFd, IOCTL_KGSL_GPUOBJ_IMPORT, &user_mem_import)};
+    if (ret)
+        goto err;
+
+    info.id = user_mem_import.id;
+    ret = ioctl(kgslFd, IOCTL_KGSL_GPUOBJ_INFO, &info);
+    if (ret)
+        goto err;
+
+    outMapping->host_ptr = hostPtr;
+    outMapping->gpu_addr = info.gpuaddr;
+    outMapping->size = size;
+    outMapping->flags = 0xc2600; //!< Unknown flags, but they are required for the mapping to work
+
+    close(kgslFd);
+    return true;
+
+err:
+    close(kgslFd);
+    return false;
+}
+
+bool adrenotools_validate_gpu_mapping(adrenotools_gpu_mapping *mapping) {
+    return mapping->gpu_addr == ADRENOTOOLS_GPU_MAPPING_SUCCEEDED_MAGIC;
+}

src/hook/CMakeLists.txt

@@ -18,3 +18,10 @@ target_compile_options(file_redirect_hook PRIVATE -Wall -Wextra)
 target_link_options(file_redirect_hook PRIVATE -z global)
 target_link_libraries(file_redirect_hook hook_impl)
 set_target_properties(file_redirect_hook PROPERTIES CXX_VISIBILITY_PRESET hidden)
+
+add_library(gsl_alloc_hook SHARED gsl_alloc_hook.c)
+
+target_compile_options(gsl_alloc_hook PRIVATE -Wall -Wextra)
+target_link_options(gsl_alloc_hook PRIVATE -z global)
+target_link_libraries(gsl_alloc_hook hook_impl)
+set_target_properties(gsl_alloc_hook PROPERTIES CXX_VISIBILITY_PRESET hidden)

src/hook/gsl_alloc_hook.c

@@ -0,0 +1,9 @@
+#include "hook_impl.h"
+
+__attribute__((visibility("default"))) int gsl_memory_alloc_pure(uint32_t size, uint32_t flags, void *memDesc) {
+	return hook_gsl_memory_alloc_pure(size, flags, memDesc);
+}
+
+__attribute__((visibility("default"))) int gsl_memory_free_pure(void *memDesc) {
+	return hook_gsl_memory_free_pure(memDesc);
+}

src/hook/hook_impl.cpp

@@ -3,9 +3,12 @@
 #include <cstdio>
 #include <cstring>
 #include <dlfcn.h>
+#include <fcntl.h>
+#include <sys/ioctl.h>
 #include <android_linker_ns.h>
 #include <android/dlext.h>
 #include <android/log.h>
+#include "kgsl.h"
 #include "hook_impl_params.h"
 #include "hook_impl.h"
 
@@ -13,11 +16,22 @@
 #define LOGI(fmt, ...) __android_log_print(ANDROID_LOG_INFO, TAG, fmt, ##__VA_ARGS__)
 
 const HookImplParams *hook_params; //!< Bunch of info needed to load/patch the driver
+int (*gsl_memory_alloc_pure_sym)(uint32_t, uint32_t, void *);
+int (*gsl_memory_free_pure_sym)(void *);
+int kgsl_fd;
+
+using gsl_memory_alloc_pure_t = decltype(gsl_memory_alloc_pure_sym);
+using gsl_memory_free_pure_t = decltype(gsl_memory_free_pure_sym);
 
 __attribute__((visibility("default"))) void init_hook_param(const void *param) {
     hook_params = reinterpret_cast<const HookImplParams *>(param);
 }
 
+__attribute__((visibility("default"))) void init_gsl(void *alloc, void *free) {
+    gsl_memory_alloc_pure_sym = reinterpret_cast<gsl_memory_alloc_pure_t>(alloc);
+    gsl_memory_free_pure_sym = reinterpret_cast<gsl_memory_free_pure_t>(free);
+}
+
 __attribute__((visibility("default"))) void *hook_android_dlopen_ext(const char *filename, int flags, const android_dlextinfo *extinfo) {
     auto fallback{[&]() {
         LOGI("hook_android_dlopen_ext: falling back!");
@@ -46,7 +60,7 @@ __attribute__((visibility("default"))) void *hook_android_dlopen_ext(const char
 
     // We depend on libandroid which is unlikely to be in the supplied driver namespace so we have to link it over
     android_link_namespaces(driverNs, nullptr, "libandroid.so");
-    
+
     // Preload ourself, a new instance will be created since we have different linker ancestory
     // If we don't preload we get a weird issue where despite being in NEEDED of the hook lib the hook's symbols will overwrite ours and cause an infinite loop
     auto hookImpl{linkernsbypass_namespace_dlopen("libhook_impl.so", RTLD_NOW, driverNs)};
@@ -57,7 +71,7 @@ __attribute__((visibility("default"))) void *hook_android_dlopen_ext(const char
     auto initHookParam{reinterpret_cast<void (*)(const void *)>(dlsym(hookImpl, "init_hook_param"))};
     if (!initHookParam)
         return nullptr;
-    
+
     initHookParam(hook_params);
 
     if (hook_params->featureFlags & ADRENOTOOLS_DRIVER_FILE_REDIRECT) {
@@ -73,7 +87,38 @@ __attribute__((visibility("default"))) void *hook_android_dlopen_ext(const char
     auto newExtinfo{*extinfo};
     newExtinfo.library_namespace = driverNs;
 
-    // TODO: If there is already an instance of a vulkan driver loaded hooks won't be applied, this will only be the case for skiavk generally
+    if (hook_params->featureFlags & ADRENOTOOLS_DRIVER_GPU_MAPPING_IMPORT) {
+        if (!linkernsbypass_namespace_dlopen("libgsl_alloc_hook.so", RTLD_GLOBAL, driverNs)) {
+            LOGI("hook_android_dlopen_ext: hook failed: failed to apply libgsl_alloc_hook!");
+            return fallback();
+        }
+
+        auto libgslHandle{android_dlopen_ext("libgsl.so", RTLD_NOW, &newExtinfo)};
+        if (!libgslHandle) {
+            libgslHandle = android_dlopen_ext("notgsl.so", RTLD_NOW, &newExtinfo);
+            if (!libgslHandle)
+                libgslHandle = android_dlopen_ext("vkbgsl.so", RTLD_NOW, &newExtinfo);
+        }
+
+        if (libgslHandle) {
+            gsl_memory_alloc_pure_sym = reinterpret_cast<decltype(gsl_memory_alloc_pure_sym)>(dlsym(libgslHandle, "gsl_memory_alloc_pure"));
+            gsl_memory_free_pure_sym = reinterpret_cast<decltype(gsl_memory_free_pure_sym)>(dlsym(libgslHandle, "gsl_memory_free_pure"));
+            if (gsl_memory_alloc_pure_sym && gsl_memory_free_pure_sym) {
+                auto initGsl{reinterpret_cast<void (*)(gsl_memory_alloc_pure_t, gsl_memory_free_pure_t)>(dlsym(hookImpl, "init_gsl"))};
+                if (!initGsl)
+                    return fallback();
+
+                initGsl(gsl_memory_alloc_pure_sym, gsl_memory_free_pure_sym);
+                LOGI("hook_android_dlopen_ext: applied libgsl_alloc_hook");
+                hook_params->nextGpuMapping->gpu_addr = ADRENOTOOLS_GPU_MAPPING_SUCCEEDED_MAGIC;
+            }
+        }
+
+        if (!gsl_memory_alloc_pure_sym || !gsl_memory_free_pure_sym)
+            LOGI("hook_android_dlopen_ext: hook failed: failed to apply libgsl_alloc_hook!");
+    }
+
+    // TODO: If there is already an instance of a Vulkan driver loaded hooks won't be applied, this will only be the case for skiavk generally
     // To fix this we would need to search /proc/self/maps for the file to a loaded instance of the library in order to read it to patch the soname and load it uniquely
     if (hook_params->featureFlags & ADRENOTOOLS_DRIVER_CUSTOM) {
         LOGI("hook_android_dlopen_ext: loading custom driver: %s%s", hook_params->customDriverDir.c_str(), hook_params->customDriverName.c_str());
@@ -92,7 +137,7 @@ __attribute__((visibility("default"))) void *hook_android_dlopen_ext(const char
 
 __attribute__((visibility("default"))) void *hook_android_load_sphal_library(const char *filename, int flags) {
     LOGI("hook_android_load_sphal_library: filename: %s", filename);
-    
+
     // https://android.googlesource.com/platform/system/core/+/master/libvndksupport/linker.cpp
     for (const char *name : {"sphal", "vendor", "default"}) {
         if (auto vendorNs{android_get_exported_namespace(name)}) {
@@ -107,7 +152,7 @@ __attribute__((visibility("default"))) void *hook_android_load_sphal_library(con
 
     return nullptr;
 }
-    
+
 __attribute__((visibility("default"))) FILE *hook_fopen(const char *filename, const char *mode) {
     if (!strncmp("/proc", filename, 5) || !strncmp("/sys", filename, 4)) {
         LOGI("hook_fopen: passthrough: %s", filename);
@@ -119,3 +164,60 @@ __attribute__((visibility("default"))) FILE *hook_fopen(const char *filename, co
 
     return fopen(replacement.c_str(), mode);
 }
+
+static constexpr uintptr_t GslMemDescImportedPrivMagic{0xdeadb33f};
+struct GslMemDesc {
+    void *hostptr;
+    uint64_t gpuaddr;
+    uint64_t size;
+    uint64_t flags;
+    uintptr_t priv;
+};
+
+__attribute__((visibility("default"))) int hook_gsl_memory_alloc_pure(uint32_t size, uint32_t flags, void *memDesc) {
+    auto gslMemDesc{reinterpret_cast<GslMemDesc *>(memDesc)};
+
+    if (hook_params->nextGpuMapping && hook_params->nextGpuMapping->size == size && (hook_params->nextGpuMapping->flags & flags) == flags) {
+        auto &nextMapping{*hook_params->nextGpuMapping};
+
+        gslMemDesc->hostptr = nextMapping.host_ptr;
+        gslMemDesc->gpuaddr = nextMapping.gpu_addr;
+        gslMemDesc->size = nextMapping.size;
+        gslMemDesc->flags = nextMapping.flags;
+        gslMemDesc->priv = GslMemDescImportedPrivMagic;
+        hook_params->nextGpuMapping->size = 0;
+        hook_params->nextGpuMapping->gpu_addr = ADRENOTOOLS_GPU_MAPPING_SUCCEEDED_MAGIC;
+        return 0;
+    } else {
+        return gsl_memory_alloc_pure_sym(size, flags, gslMemDesc);
+    }
+}
+
+__attribute__((visibility("default"))) int hook_gsl_memory_free_pure(void *memDesc) {
+    auto gslMemDesc{reinterpret_cast<GslMemDesc *>(memDesc)};
+
+    if (gslMemDesc->priv == GslMemDescImportedPrivMagic) {
+        if (!kgsl_fd)
+            kgsl_fd = open("/dev/kgsl-3d0", O_RDWR);
+
+        kgsl_gpumem_get_info info{
+            .gpuaddr = gslMemDesc->gpuaddr
+        };
+
+        if (ioctl(kgsl_fd, IOCTL_KGSL_GPUMEM_GET_INFO, &info) < 0) {
+            LOGI("IOCTL_KGSL_GPUMEM_GET_INFO failed");
+            return 0;
+        }
+
+        kgsl_gpuobj_free args{
+            .id = info.id,
+        };
+
+        if (ioctl(kgsl_fd, IOCTL_KGSL_GPUOBJ_FREE, &args) < 0)
+            LOGI("IOCTL_KGSL_GPUOBJ_FREE failed");
+
+        return 0;
+    } else {
+        return gsl_memory_free_pure_sym(memDesc);
+    }
+}

src/hook/hook_impl.h

@@ -11,13 +11,18 @@ extern "C" {
 #include <android/dlext.h>
 
 void init_hook_param(const void *param);
-	
+
+void init_gsl(void *alloc, void *free);
+
 void *hook_android_dlopen_ext(const char *filename, int flags, const android_dlextinfo *extinfo);
 
 void *hook_android_load_sphal_library(const char *filename, int flags);
 
 FILE *hook_fopen(const char *filename, const char *mode);
 
+int hook_gsl_memory_alloc_pure(uint32_t size, uint32_t flags, void *memDesc);
+
+int hook_gsl_memory_free_pure(void *memDesc);
 
 #ifdef __cplusplus
 }

src/hook/hook_impl_params.h

@@ -17,13 +17,15 @@ struct HookImplParams {
     std::string customDriverDir;
     std::string customDriverName;
     std::string fileRedirectDir;
+    adrenotools_gpu_mapping *nextGpuMapping;
 
     HookImplParams(int featureFlags, const char *tmpLibDir, const char *hookLibDir, const char *customDriverDir,
-				   const char *customDriverName, const char *fileRedirectDir)
+                  const char *customDriverName, const char *fileRedirectDir, adrenotools_gpu_mapping *nextGpuMapping)
         : featureFlags(featureFlags),
           tmpLibDir(tmpLibDir ? tmpLibDir : ""),
           hookLibDir(hookLibDir),
           customDriverDir(customDriverDir ? customDriverDir : ""),
           customDriverName(customDriverName ? customDriverName : ""),
-          fileRedirectDir(fileRedirectDir ? fileRedirectDir : "") {}
+          fileRedirectDir(fileRedirectDir ? fileRedirectDir : ""),
+          nextGpuMapping(nextGpuMapping) {}
 };