Added subject module

subject/CMakeLists.txt

@@ -11,7 +11,7 @@ file(MAKE_DIRECTORY "${SUBJECT_SPSLR_METADIR}")
 
 add_library(subject_objs OBJECT ${SUBJECT_SRC})
 target_include_directories(subject_objs PRIVATE .)
-target_link_libraries(subject_objs PRIVATE spslr_selfpatch)
+target_link_libraries(subject_objs PRIVATE spslr_selfpatch dl)
 add_dependencies(subject_objs spslr_pinpoint)
 
 target_compile_options(subject_objs PRIVATE
@@ -66,3 +66,73 @@ target_include_directories(subject PRIVATE .)
 target_link_libraries(subject PRIVATE spslr_selfpatch)
 add_dependencies(subject spslr_selfpatch)
 
+
+
+set(MODULE_SRC
+	module.c
+)
+
+set(MODULE_SPSLR_METADIR "${CMAKE_CURRENT_BINARY_DIR}/spslr_module")
+set(MODULE_SPSLR_SRCROOT "${CMAKE_CURRENT_SOURCE_DIR}")
+
+file(MAKE_DIRECTORY "${MODULE_SPSLR_METADIR}")
+
+add_library(spslr_module_objs OBJECT ${MODULE_SRC})
+target_include_directories(spslr_module_objs PRIVATE .)
+add_dependencies(spslr_module_objs spslr_pinpoint)
+
+target_compile_options(spslr_module_objs PRIVATE
+	-O1
+	-fPIC
+	-fplugin=$<TARGET_FILE:spslr_pinpoint>
+	-fplugin-arg-spslr_pinpoint-srcroot=${MODULE_SPSLR_SRCROOT}
+	-fplugin-arg-spslr_pinpoint-metadir=${MODULE_SPSLR_METADIR}
+)
+
+set(MODULE_SPSLR_FILES "")
+foreach(src IN LISTS MODULE_SRC)
+	get_filename_component(abs_src "${src}" ABSOLUTE BASE_DIR "${CMAKE_CURRENT_SOURCE_DIR}")
+	file(RELATIVE_PATH rel_src "${MODULE_SPSLR_SRCROOT}" "${abs_src}")
+	file(TO_CMAKE_PATH "${rel_src}" rel_src)
+	list(APPEND MODULE_SPSLR_FILES "${MODULE_SPSLR_METADIR}/${rel_src}.spslr")
+endforeach()
+
+set(MODULE_SPSLR_ASM "${CMAKE_CURRENT_BINARY_DIR}/spslr_module_program.S")
+set(MODULE_SPSLR_OBJ "${CMAKE_CURRENT_BINARY_DIR}/spslr_module_program.o")
+
+add_custom_command(
+	OUTPUT "${MODULE_SPSLR_ASM}"
+	COMMAND $<TARGET_FILE:spslr_patchcompile>
+		--out=${MODULE_SPSLR_ASM}
+		${MODULE_SPSLR_FILES}
+	DEPENDS
+		spslr_patchcompile
+		$<TARGET_OBJECTS:spslr_module_objs>
+	VERBATIM
+)
+
+add_custom_command(
+	OUTPUT "${MODULE_SPSLR_OBJ}"
+	COMMAND ${CMAKE_C_COMPILER}
+		-fPIC
+		-c "${MODULE_SPSLR_ASM}"
+		-o "${MODULE_SPSLR_OBJ}"
+	DEPENDS "${MODULE_SPSLR_ASM}"
+	VERBATIM
+)
+
+set_source_files_properties("${MODULE_SPSLR_OBJ}" PROPERTIES
+	GENERATED TRUE
+	EXTERNAL_OBJECT TRUE
+)
+
+add_library(spslr_module SHARED
+	$<TARGET_OBJECTS:spslr_module_objs>
+	"${MODULE_SPSLR_OBJ}"
+)
+
+target_include_directories(spslr_module PRIVATE .)
+set_target_properties(spslr_module PROPERTIES
+	OUTPUT_NAME "spslr_module"
+	PREFIX "lib"
+)

subject/main.c

@@ -1,5 +1,9 @@
 #include <spslr.h>
 
+#include <dlfcn.h>
+#include <stdio.h>
+#include <stdlib.h>
+
 #include "task_struct.h"
 #include "export.h"
 
@@ -18,6 +22,32 @@ struct task_struct global = { .pid = 42, .comm = "main_global", .arrfun = {
 
 EXPORT_SYMBOL(global);
 
+static int do_module_test_access_pid(const char *path, const struct task_struct *t) {
+	typedef int (*module_test_access_fn)(const struct task_struct *t);
+
+	void *handle = dlopen(path, RTLD_NOW | RTLD_LOCAL);
+	if (!handle) {
+		fprintf(stderr, "dlopen failed for %s: %s\n", path, dlerror());
+		return -1;
+	}
+
+	dlerror();
+
+	module_test_access_fn fn = (module_test_access_fn)dlsym(handle, "module_test_access_pid");
+
+	const char *err = dlerror();
+	if (err) {
+		fprintf(stderr, "dlsym failed: %s\n", err);
+		dlclose(handle);
+		return -1;
+	}
+
+	int ret = fn(t);
+
+	dlclose(handle);
+	return ret;
+}
+
 static void print_layout() {
     // TODO -> Make builtin __spslr_initial_offsetof(type, field) that is not patched
     printf("Current task_struct layout:\n");
@@ -77,6 +107,9 @@ int main(void)
 
 	arr_test();
 
+	int module_pid = do_module_test_access_pid("./subject/libspslr_module.so", &global);
+	printf("module_test_access returned %d (should be 42)\n", module_pid);
+
     return 0;
 }
 

subject/module.c

@@ -0,0 +1,5 @@
+#include "module.h"
+
+int module_test_access_pid(const struct task_struct* t) {
+	return t->pid;
+}

subject/module.h

@@ -0,0 +1,3 @@
+#include "task_struct.h"
+
+int module_test_access_pid(const struct task_struct* t);

subject/task_struct.h

@@ -1,3 +1,6 @@
+#ifndef HDR_TASK_STRUCT
+#define HDR_TASK_STRUCT
+
 #include <stdio.h>
 #include <stddef.h>
 
@@ -81,3 +84,4 @@ struct task_struct {
 	int stuck1, stuck2;
 };
 
+#endif