DynamicLoader+LibC: Link LibC into DynamicLoader --as-sane-people

Meta/CMake/utils.cmake

@@ -9,15 +9,6 @@ function(serenity_set_implicit_links target_name)
     # slightly outdated stub in the sysroot, but have not yet installed the freshly
     # built LibC.
     target_link_libraries(${target_name} PRIVATE LibC)
-
-    # Same goes for -lssp_nonshared, which is required during build time but is not
-    # yet installed in the sysroot. However, we just want to add the link directory
-    # and a dependency here, since actually linking the library is decided on by
-    # passing one of the -fstack-protector options.
-    # -lssp is contained inside LibC, so that case is handled by the above and a linker
-    # script.
-    target_link_directories(${target_name} PRIVATE "$<TARGET_FILE_DIR:ssp_nonshared>")
-    add_dependencies(${target_name} ssp_nonshared)
 endfunction()
 
 function(serenity_install_headers target_name)

Toolchain/Patches/gcc/0001-Add-a-gcc-driver-for-SerenityOS.patch

@@ -87,7 +87,7 @@ new file mode 100644
 index 0000000000000000000000000000000000000000..10c6f16fbe13eab36bab8f6896f8e2a6ae48df02
 --- /dev/null
 +++ b/gcc/config/serenity.h
-@@ -0,0 +1,48 @@
+@@ -0,0 +1,50 @@
 +/* Useful if you wish to make target-specific GCC changes. */
 +#undef TARGET_SERENITY
 +#define TARGET_SERENITY 1
@@ -110,6 +110,8 @@ index 0000000000000000000000000000000000000000..10c6f16fbe13eab36bab8f6896f8e2a6
 +#undef ENDFILE_SPEC
 +#define ENDFILE_SPEC "%{shared|static-pie|!no-pie:crtendS.o%s; :crtend.o%s} crtn.o%s"
 +
++#define TARGET_LIBC_PROVIDES_SSP
++
 +#undef LINK_SPEC
 +#define LINK_SPEC "%{shared:-shared} %{static:-static} %{!static: %{rdynamic:-export-dynamic} -dynamic-linker /usr/lib/Loader.so}"
 +

Userland/DynamicLoader/CMakeLists.txt

@@ -1,64 +1,21 @@
-set(LOADER_SOURCES
+set(SOURCES
     main.cpp
     misc.cpp
 )
 
 add_library(DynamicLoader_CompileOptions INTERFACE)
-target_compile_options(DynamicLoader_CompileOptions INTERFACE -fno-rtti -fpie)
-target_link_options(DynamicLoader_CompileOptions INTERFACE -nostdlib -fpie)
-target_compile_definitions(DynamicLoader_CompileOptions INTERFACE NO_TLS)
+target_compile_definitions(DynamicLoader_CompileOptions INTERFACE NO_TLS _DYNAMIC_LOADER)
+target_compile_options(DynamicLoader_CompileOptions INTERFACE -fno-rtti -fpie -ffunction-sections -fdata-sections)
+target_link_options(DynamicLoader_CompileOptions INTERFACE -nolibc -nostdlib++ -nostartfiles -static-libgcc -fpie -Wl,--gc-sections)
+target_link_options(DynamicLoader_CompileOptions INTERFACE -fno-sanitize=undefined) # Sanitizer runtime is linked in manually
 add_dependencies(DynamicLoader_CompileOptions install_libc_headers)
 
-file(GLOB LIBC_SOURCES1 "../Libraries/LibC/*.cpp")
-file(GLOB LIBC_SOURCES2 "../Libraries/LibC/*/*.cpp")
-
-set(ARCH_FOLDER "${SERENITY_ARCH}")
-
-file(GLOB LIBC_SOURCES3 "../Libraries/LibC/arch/${ARCH_FOLDER}/*.S")
-set(LIBC_SOURCES3 ${LIBC_SOURCES3} "../Libraries/LibC/arch/${ARCH_FOLDER}/fenv.cpp")
-if ("${SERENITY_ARCH}" STREQUAL "x86_64")
-    set(LIBC_SOURCES3 ${LIBC_SOURCES3} "../Libraries/LibC/arch/x86_64/memset.cpp")
-endif()
-
-file(GLOB LIBSYSTEM_SOURCES "../Libraries/LibSystem/*.cpp")
+add_executable(Loader.so ${SOURCES})
 
+target_link_libraries(Loader.so PRIVATE DynamicLoader_CompileOptions DynamicLoader_LibELF)
 if (ENABLE_UNDEFINED_SANITIZER)
-    set(LOADER_SOURCES ${LOADER_SOURCES} ../Libraries/LibSanitizer/UBSanitizer.cpp)
+    target_link_libraries(Loader.so PRIVATE DynamicLoader_LibUBSanitizer)
 endif()
-
-# pthread requires thread local storage, which DynamicLoader does not have.
-list(FILTER LIBC_SOURCES1 EXCLUDE REGEX ".*/LibC/(pthread|semaphore)\\.cpp")
-
-add_definitions(-D_DYNAMIC_LOADER)
-
-set(SOURCES ${LOADER_SOURCES} ${AK_SOURCES} ${LIBC_SOURCES1} ${LIBC_SOURCES2} ${LIBC_SOURCES3} ${LIBSYSTEM_SOURCES})
-
-if (("${SERENITY_ARCH}" STREQUAL "aarch64") OR ("${SERENITY_ARCH}" STREQUAL "riscv64"))
-    # On aarch64 and riscv64 the stack protector would be accessed before the Loader can relocate itself.
-    set_source_files_properties(main.cpp PROPERTIES COMPILE_FLAGS "-fno-stack-protector")
-endif()
-
-set_source_files_properties(../Libraries/LibC/ssp.cpp PROPERTIES COMPILE_FLAGS "-fno-stack-protector")
-set_source_files_properties(../Libraries/LibC/ssp_nonshared.cpp PROPERTIES COMPILE_FLAGS "-fno-stack-protector")
-# Prevent GCC from removing null checks by marking the `FILE*` argument non-null
-set_source_files_properties(../Libraries/LibC/stdio.cpp PROPERTIES COMPILE_FLAGS "-fno-builtin-fputc -fno-builtin-fputs -fno-builtin-fwrite")
-
-# Prevent naively implemented string functions (like strlen) from being "optimized" into a call to themselves.
-if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    set_source_files_properties(../Libraries/LibC/string.cpp ../Libraries/LibC/wchar.cpp
-        PROPERTIES COMPILE_FLAGS "-fno-tree-loop-distribution -fno-tree-loop-distribute-patterns")
-endif()
-
-add_executable(Loader.so ${SOURCES})
-add_dependencies(Loader.so install_libc_headers)
-
-if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
-    target_link_libraries(Loader.so PRIVATE gcc)
-elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang$")
-    target_link_libraries(Loader.so PRIVATE clang_rt.builtins)
-endif ()
-
-target_link_libraries(Loader.so PRIVATE DynamicLoader_CompileOptions DynamicLoader_LibELF LibTimeZone)
 target_link_options(Loader.so PRIVATE LINKER:--no-dynamic-linker)
 # Don't confuse the coverage results by instrumenting Loader
 target_link_libraries(Loader.so PRIVATE NoCoverage)

Userland/DynamicLoader/main.cpp

@@ -108,7 +108,7 @@ ALWAYS_INLINE static void optimizer_fence()
     asm("" ::: "memory");
 }
 
-void _entry(int argc, char** argv, char** envp)
+[[gnu::no_stack_protector]] void _entry(int argc, char** argv, char** envp)
 {
     char** env;
     for (env = envp; *env; ++env) {