Merge pull request #44 from GBuella/static_test

Fix static library

Author: Sarah Jelinek

CMakeLists.txt

@@ -29,7 +29,7 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-cmake_minimum_required(VERSION 2.8.7)
+cmake_minimum_required(VERSION 3.3)
 project(syscall_intercept C CXX ASM)
 
 set(CMAKE_DISABLE_IN_SOURCE_BUILD ON)
@@ -60,7 +60,7 @@ include(GNUInstallDirs)
 include(cmake/toolchain_features.cmake)
 include(cmake/find_capstone.cmake)
 
-# main source files - intentionally excluding src/entry.c
+# main source files - intentionally excluding src/cmdline_filter.c
 set(SOURCES_C
 	src/disasm_wrapper.c
 	src/intercept.c
@@ -83,8 +83,9 @@ set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 # can use the internal interface of the libraries (linking
 # with syscall_intercept_base instead of the actual lib ), without
 # the library trying to hotpatch libc every time.
-add_library(syscall_intercept_base_c STATIC ${SOURCES_C})
-add_library(syscall_intercept_base_asm STATIC ${SOURCES_ASM})
+add_library(syscall_intercept_base_c OBJECT ${SOURCES_C})
+add_library(syscall_intercept_base_asm OBJECT ${SOURCES_ASM})
+add_library(syscall_intercept_base_clf OBJECT src/cmdline_filter.c)
 
 if(HAS_NOUNUSEDARG)
 	target_compile_options(syscall_intercept_base_asm BEFORE
@@ -94,36 +95,42 @@ endif()
 set_property(TARGET syscall_intercept_base_c
 	APPEND PROPERTY COMPILE_FLAGS ${capstone_CFLAGS})
 
-target_link_libraries(syscall_intercept_base_c
-	${CMAKE_DL_LIBS} ${capstone_LIBRARIES})
+add_library(syscall_intercept_unscoped STATIC
+		$<TARGET_OBJECTS:syscall_intercept_base_c>
+		$<TARGET_OBJECTS:syscall_intercept_base_asm>
+		$<TARGET_OBJECTS:syscall_intercept_base_clf>)
+
+set(syscall_intercept_unscoped_a $<TARGET_FILE:syscall_intercept_unscoped>)
+
+add_custom_command(
+	OUTPUT syscall_intercept_scoped.o
+	COMMAND ${CMAKE_LINKER}
+		-r --whole-archive ${syscall_intercept_unscoped_a}
+		-o syscall_intercept_scoped.o
+	COMMAND ${CMAKE_OBJCOPY} --localize-hidden syscall_intercept_scoped.o
+	COMMENT "Hiding symbols")
+
+add_library(syscall_intercept_shared SHARED syscall_intercept_scoped.o)
+add_library(syscall_intercept_static STATIC syscall_intercept_scoped.o)
+
+set_target_properties(syscall_intercept_base_c
+		PROPERTIES C_VISIBILITY_PRESET hidden)
 
-add_library(syscall_intercept_shared SHARED src/entry.c)
 target_link_libraries(syscall_intercept_shared
-	syscall_intercept_base_c syscall_intercept_base_asm)
-add_library(syscall_intercept_static STATIC src/entry.c)
+	PRIVATE ${CMAKE_DL_LIBS} ${capstone_LIBRARIES})
+
 target_link_libraries(syscall_intercept_static
-	syscall_intercept_base_c syscall_intercept_base_asm)
+	INTERFACE ${CMAKE_DL_LIBS} ${capstone_LIBRARIES})
 
 set_target_properties(syscall_intercept_shared
 	PROPERTIES VERSION ${SYSCALL_INTERCEPT_VERSION}
 		   SOVERSION ${SYSCALL_INTERCEPT_VERSION_MAJOR})
 
 add_executable(cpp_test src/cpp_compile_test.cc src/cpp_compile_mock.c)
 
-if(CMAKE_OBJCOPY)
-foreach(target syscall_intercept_shared syscall_intercept_static)
-	add_custom_command(TARGET ${target}
-	POST_BUILD COMMAND ${CMAKE_OBJCOPY}
-	--localize-hidden
-	-G intercept_hook_point
-	-G syscall_no_intercept
-	-G libc_hook_in_process_allowed
-	$<TARGET_FILE:${target}>)
-endforeach()
-endif()
-
 set_target_properties(syscall_intercept_shared syscall_intercept_static
 	PROPERTIES
+	LINKER_LANGUAGE C
 	PUBLIC_HEADER "include/libsyscall_intercept_hook_point.h"
 	OUTPUT_NAME syscall_intercept)
 

src/entry.c src/cmdline_filter.csrc/entry.c renamed to src/cmdline_filter.c

@@ -30,11 +30,6 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
-/*
- * entry.c -- the entry point for libsyscall_intercept
- *  expected to be executed by the loader while using LD_PRELOAD
- */
-
 #include <stdbool.h>
 #include <stdlib.h>
 #include <string.h>
@@ -45,28 +40,6 @@
 #include "libsyscall_intercept_hook_point.h"
 #include "intercept.h"
 
-static const char *cmdline;
-
-/*
- * entry_point - the main entry point for syscall_intercept
- *
- * The loader calls this routine once the library is loaded, except in certain
- * cases when testing -- see asm_wrapper.c for more details.
- * The actual work of hotpatching libraries is done the routine
- * called intercept.
- */
-static __attribute__((constructor)) void
-entry_point(int argc, char **argv)
-{
-	if (argc < 1)
-		return;
-
-	cmdline = argv[0];
-
-	if (syscall_hook_in_process_allowed())
-		intercept();
-}
-
 /*
  * cmdline_match - match the last component of the path in cmdline
  */
@@ -112,6 +85,9 @@ syscall_hook_in_process_allowed(void)
 	if (is_decided)
 		return result;
 
+	if (cmdline == NULL)
+		return 0;
+
 	result = cmdline_match(getenv("INTERCEPT_HOOK_CMDLINE_FILTER"));
 	is_decided = true;
 

src/intercept.c

@@ -63,9 +63,11 @@ int (*intercept_hook_point)(long syscall_number,
 			long arg0, long arg1,
 			long arg2, long arg3,
 			long arg4, long arg5,
-			long *result);
+			long *result)
+	__attribute__((visibility("default")));
 
-void (*intercept_hook_point_clone_child)(void);
+void (*intercept_hook_point_clone_child)(void)
+	__attribute__((visibility("default")));
 
 bool debug_dumps_on;
 
@@ -306,7 +308,15 @@ is_vdso(uintptr_t addr, const char *path)
 static bool
 should_patch_object(uintptr_t addr, const char *path)
 {
-	static const char self[] = "libsyscall_intercept";
+	static uintptr_t self_addr;
+	if (self_addr == 0) {
+		extern unsigned char intercept_asm_wrapper_tmpl[];
+		Dl_info self;
+		if (!dladdr((void *)&intercept_asm_wrapper_tmpl, &self))
+			xabort("self dladdr failure");
+		self_addr = (uintptr_t)self.dli_fbase;
+	}
+
 	static const char libc[] = "libc";
 	static const char pthr[] = "libpthread";
 	static const char caps[] = "libcapstone";
@@ -322,7 +332,7 @@ should_patch_object(uintptr_t addr, const char *path)
 	if (len == 0)
 		return false;
 
-	if (str_match(name, len, self)) {
+	if (addr == self_addr) {
 		debug_dump(" - skipping: matches self\n");
 		return false;
 	}
@@ -403,15 +413,28 @@ analyze_object(struct dl_phdr_info *info, size_t size, void *data)
 	return 0;
 }
 
+const char *cmdline;
+
 /*
  * intercept - This is where the highest level logic of hotpatching
  * is described. Upon startup, this routine looks for libc, and libpthread.
  * If these libraries are found in the process's address space, they are
  * patched.
+ *
+ * This is init routine of syscall_intercept. This library constructor
+ * must be in a TU which also contains public symbols, otherwise linkers
+ * might just get rid of the whole object file containing it, when linking
+ * statically with libsyscall_intercept.
  */
-void
-intercept(void)
+static __attribute__((constructor)) void
+intercept(int argc, char **argv)
 {
+	(void) argc;
+	cmdline = argv[0];
+
+	if (!syscall_hook_in_process_allowed())
+		return;
+
 	vdso_addr = (void *)(uintptr_t)getauxval(AT_SYSINFO_EHDR);
 	debug_dumps_on = getenv("INTERCEPT_DEBUG_DUMP") != NULL;
 	patch_all_objs = (getenv("INTERCEPT_ALL_OBJS") != NULL);

src/intercept.h

@@ -225,6 +225,6 @@ bool is_overwritable_nop(const struct intercept_disasm_result *ins);
 
 void create_jump(unsigned char opcode, unsigned char *from, void *to);
 
-void intercept(void);
+const char *cmdline;
 
 #endif

src/intercept_template.s

@@ -214,35 +214,61 @@
  */
 
 .global backtrace_placeholder;
+.hidden backtrace_placeholder;
 .type   backtrace_placeholder, @function
 
 .global backtrace_placeholder_2;
+.hidden backtrace_placeholder_2;
 .type   backtrace_placeholder_2, @function
 
 .global intercept_asm_wrapper_tmpl;
+.hidden intercept_asm_wrapper_tmpl;
 .global intercept_asm_wrapper_simd_save;
+.hidden intercept_asm_wrapper_simd_save;
 .global intercept_asm_wrapper_prefix;
+.hidden intercept_asm_wrapper_prefix;
 .global intercept_asm_wrapper_push_origin_addr;
+.hidden intercept_asm_wrapper_push_origin_addr;
 .global intercept_asm_wrapper_mov_return_addr_r11_no_syscall;
+.hidden intercept_asm_wrapper_mov_return_addr_r11_no_syscall;
 .global intercept_asm_wrapper_mov_return_addr_r11_syscall;
+.hidden intercept_asm_wrapper_mov_return_addr_r11_syscall;
 .global intercept_asm_wrapper_mov_libpath_r11;
+.hidden intercept_asm_wrapper_mov_libpath_r11;
 .global intercept_asm_wrapper_mov_phaddr_r11;
+.hidden intercept_asm_wrapper_mov_phaddr_r11;
 .global intercept_asm_wrapper_mov_ph2addr_r11;
+.hidden intercept_asm_wrapper_mov_ph2addr_r11;
 .global intercept_asm_wrapper_call;
+.hidden intercept_asm_wrapper_call;
 .global intercept_asm_wrapper_simd_restore;
+.hidden intercept_asm_wrapper_simd_restore;
 .global intercept_asm_wrapper_postfix;
+.hidden intercept_asm_wrapper_postfix;
 .global intercept_asm_wrapper_return_jump;
+.hidden intercept_asm_wrapper_return_jump;
 .global intercept_asm_wrapper_end;
+.hidden intercept_asm_wrapper_end;
 .global intercept_asm_wrapper_simd_save_YMM;
+.hidden intercept_asm_wrapper_simd_save_YMM;
 .global intercept_asm_wrapper_simd_save_YMM_end;
+.hidden intercept_asm_wrapper_simd_save_YMM_end;
 .global intercept_asm_wrapper_simd_restore_YMM;
+.hidden intercept_asm_wrapper_simd_restore_YMM;
 .global intercept_asm_wrapper_simd_restore_YMM_end;
+.hidden intercept_asm_wrapper_simd_restore_YMM_end;
 .global intercept_asm_wrapper_return_and_no_syscall;
+.hidden intercept_asm_wrapper_return_and_no_syscall;
 .global intercept_asm_wrapper_return_and_syscall;
+.hidden intercept_asm_wrapper_return_and_syscall;
 .global intercept_asm_wrapper_push_stack_first_return_addr;
+.hidden intercept_asm_wrapper_push_stack_first_return_addr;
 .global intercept_asm_wrapper_mov_r11_stack_first_return_addr;
+.hidden intercept_asm_wrapper_mov_r11_stack_first_return_addr;
 .global intercept_asm_wrapper_clone_wrapper;
+.hidden intercept_asm_wrapper_clone_wrapper;
 .global intercept_asm_wrapper_call_clone_child_intercept;
+.hidden intercept_asm_wrapper_call_clone_child_intercept;
 
 .text
 

src/util.s

@@ -31,9 +31,11 @@
  */
 
 .global xlongjmp;
+.hidden xlongjmp;
 .type   xlongjmp, @function
 
 .global has_ymm_registers;
+.hidden has_ymm_registers;
 .type   has_ymm_registers, @function
 
 .global syscall_no_intercept;

test/CMakeLists.txt

@@ -41,10 +41,12 @@ include_directories(${PROJECT_SOURCE_DIR}/src ${PROJECT_SOURCE_DIR}/test)
 
 set(CMAKE_ASM_CREATE_SHARED_LIBRARY ${CMAKE_C_CREATE_SHARED_LIBRARY})
 
-add_executable(asm_pattern asm_pattern.c)
+add_executable(asm_pattern asm_pattern.c
+		$<TARGET_OBJECTS:syscall_intercept_base_c>
+		$<TARGET_OBJECTS:syscall_intercept_base_asm>)
+
 target_link_libraries(asm_pattern
-	PRIVATE ${CMAKE_DL_LIBS} ${capstone_LDFLAGS}
-	syscall_intercept_base_c syscall_intercept_base_asm)
+	PRIVATE ${CMAKE_DL_LIBS} ${capstone_LDFLAGS})
 
 set(asm_patterns
 	nosyscall
@@ -127,19 +129,37 @@ add_test(NAME "logging"
 	-DSECOND_MATCH_FILE=${CMAKE_CURRENT_SOURCE_DIR}/libcintercept0_child.log.match
 	${CHECK_LOG_COMMON_ARGS})
 
+add_library(hook_test_preload_o OBJECT hook_test_preload.c)
+
 add_executable(hook_test hook_test.c)
-add_library(hook_test_preload SHARED hook_test_preload.c)
-target_link_libraries(hook_test_preload PRIVATE syscall_intercept_shared)
-add_test(NAME "hook"
+
+add_library(hook_test_preload_with_shared SHARED
+	$<TARGET_OBJECTS:hook_test_preload_o>)
+target_link_libraries(hook_test_preload_with_shared PRIVATE syscall_intercept_shared)
+add_test(NAME "hook_with_shared"
+	COMMAND ${CMAKE_COMMAND}
+	-DTEST_EXTRA_PRELOAD=${TEST_EXTRA_PRELOAD}
+	-DTEST_NAME=hook
+	-DLIB_FILE=$<TARGET_FILE:hook_test_preload_with_shared>
+	-DTEST_PROG=$<TARGET_FILE:hook_test>
+	-DTEST_PROG_ARG=None
+	-DMATCH_FILE=${CMAKE_CURRENT_SOURCE_DIR}/libcintercept1.log.match
+	${CHECK_LOG_COMMON_ARGS})
+
+add_library(hook_test_preload_with_static SHARED
+	$<TARGET_OBJECTS:hook_test_preload_o>)
+target_link_libraries(hook_test_preload_with_static PRIVATE syscall_intercept_static)
+add_test(NAME "hook_with_static"
 	COMMAND ${CMAKE_COMMAND}
 	-DTEST_EXTRA_PRELOAD=${TEST_EXTRA_PRELOAD}
 	-DTEST_NAME=hook
-	-DLIB_FILE=$<TARGET_FILE:hook_test_preload>
+	-DLIB_FILE=$<TARGET_FILE:hook_test_preload_with_static>
 	-DTEST_PROG=$<TARGET_FILE:hook_test>
 	-DTEST_PROG_ARG=None
 	-DMATCH_FILE=${CMAKE_CURRENT_SOURCE_DIR}/libcintercept1.log.match
 	${CHECK_LOG_COMMON_ARGS})
 
+
 add_library(hook_test_clone_preload SHARED hook_test_clone_preload.c)
 target_link_libraries(hook_test_clone_preload PRIVATE syscall_intercept_shared)
 add_test(NAME "hook_clone"

test/asm_pattern.c

@@ -234,3 +234,18 @@ main(int argc, char **argv)
 
 	return EXIT_SUCCESS;
 }
+
+/*
+ * syscall_hook_in_process_allowed - this symbol must be provided to
+ * be able to link with syscall_intercept's objects (other then the one
+ * created from cmdline_filter.c).
+ * This symbol is referenced from intercept.c,
+ * defined once in cmdline_filter.c, and defined here as well.
+ *
+ * Note: this function is actually never called in this test.
+ */
+int
+syscall_hook_in_process_allowed(void)
+{
+	return 0;
+}