improved elf handling

include/dbg/dbg.hpp

@@ -204,6 +204,10 @@ class ProcessInfoIterator {
 		iterator end() const {
 			return pids.end();
 		}
+
+		size_t length() const {
+			return pids.length();
+		}
 };
 
 inline ProcessInfoIterator getProcesses() {

libhijacker/source/dbg.cpp

@@ -82,6 +82,8 @@ int __attribute__((noinline)) mdbg_call(DbgArg1 &arg1, DbgArg2 &arg2, DbgArg3 &a
 		int res = sceKernelDlsym(0x2001, "get_authinfo", (void **) &addr);
 		if (res > -1 && addr) {
 			_mdbg = (p_mdbg_call)(addr + 7);
+		} else {
+			puts("failed to get get_authinfo for mdbg_call");
 		}
 	}
 
@@ -98,8 +100,17 @@ IdArray getAllPids() {
 	UniquePtr<int[]> buf{new int[length]};
 	DbgGetPidsArg arg2{buf.get(), length};
 	DbgArg3 arg3{};
-	mdbg_call(arg1, arg2, arg3);
-	return {buf.get(), arg3.length};
+	int res = mdbg_call(arg1, arg2, arg3);
+	if (arg3.length != 0) {
+		return {buf.get(), arg3.length};
+	}
+	int err = errno;
+	if (res == 0) {
+		res = arg3.err;
+	}
+	printf("dbg::getAllPids failed %d %s\n", res, strerror(res));
+	printf("errno %d %s\n", err, strerror(err));
+	return nullptr;
 }
 
 IdArray getAllTids(int pid) {

libhijacker/source/elf/elf.cpp

@@ -255,34 +255,32 @@ bool Elf::parseDynamicTable() {
 
 	if (strtab == nullptr) [[unlikely]] {
 		puts("strtab not found");
-		return false;
 	}
 
-	if (strtabLength == 0) [[unlikely]] {
-		puts("strtab size not found");
+	if (strtabLength == 0 && strtab != nullptr) [[unlikely]] {
+		puts("strtab size not found but strtab exists");
 		return false;
 	}
 
 	if (symtabLength == 0) [[unlikely]] {
 		puts("symtab size not found");
-		return false;
 	}
 
 	if (symtab == nullptr) [[unlikely]] {
 		puts("symtab not found");
-		return false;
 	}
 
 	if (relatbl == nullptr) [[unlikely]] {
-		// should this be allowed?
 		puts("rela table not found");
-		return false;
 	}
 
 	if (plt == nullptr) [[unlikely]] {
-		// should this be allowed?
 		puts("plt table not found");
-		return false;
+	}
+
+	if (symtab == nullptr || strtab == nullptr) [[unlikely]] {
+		// don't need to proceed
+		return true;
 	}
 
 	List<String> names{};
@@ -759,6 +757,7 @@ bool Elf::launch() {
 	if (!processPltRelocations()) [[unlikely]] {
 		return false;
 	}
+
 	uintptr_t args = setupKernelRW();
 	if (args == 0) [[unlikely]] {
 		return false;
@@ -771,7 +770,6 @@ bool Elf::launch() {
 
 	puts("starting");
 
-	// TODO release the buffer from memory
 	return start(args);
 }
 
@@ -792,6 +790,9 @@ bool Elf::start(uintptr_t args) {
 }
 
 uintptr_t Elf::getSymbolAddress(const Elf64_Rela *__restrict rel) const {
+	if (symtab == nullptr || strtab == nullptr) [[unlikely]] {
+		return true;
+	}
 	const Elf64_Sym *__restrict sym = symtab + ELF64_R_SYM(rel->r_info);
 	if (sym->st_value != 0) {
 		// the symbol exists in our elf
@@ -810,6 +811,9 @@ uintptr_t Elf::getSymbolAddress(const Elf64_Rela *__restrict rel) const {
 }
 
 bool Elf::processRelocations() {
+	if (relatbl == nullptr) [[unlikely]] {
+		return true;
+	}
 	uint8_t *const image = data.get() + textOffset;
 	const size_t length = relaLength;
 	for (size_t i = 0; i < length; i++) {
@@ -850,6 +854,9 @@ bool Elf::processRelocations() {
 }
 
 bool Elf::processPltRelocations() {
+	if (plt == nullptr) [[unlikely]] {
+		return true;
+	}
 	uint8_t *const image = data.get() + textOffset;
 	const size_t length = pltLength;
 	for (size_t i = 0; i < length; i++) {

spawner/source/main.cpp

@@ -1,8 +1,10 @@
 #include "backtrace.hpp"
 #include "dbg.hpp"
+#include "dbg/dbg.hpp"
 #include "elf/elf.hpp"
 #include "kernel.hpp"
 #include "hijacker.hpp"
+#include "kernel/kernel.hpp"
 #include "util.hpp"
 #include <unistd.h>
 
@@ -35,7 +37,6 @@ class FileDescriptor {
 
 	void close() {
 		if (fd != -1) {
-			__builtin_printf("closing socket %d\n", fd);
 			::close(fd);
 			fd = -1;
 		}
@@ -194,6 +195,13 @@ int main() {
 	initStdout();
 	//clearFramePointer();
 	puts("main entered");
+
+	auto processes = dbg::getProcesses();
+	if (processes.length() == 0) {
+		puts("This kernel version is not yet supported :(");
+		return -1;
+	}
+
 	auto spawner = Spawner::getSpawner("SceRedisServer");
 	if (spawner == nullptr) {
 		puts("failed to get spawner for SceRedisServer");

test_elf/CMakeLists.txt

@@ -72,4 +72,6 @@ target_sources(${PROJECT_NAME} PRIVATE ${SrcFiles})
 target_link_directories	(${PROJECT_NAME} PUBLIC ${D_CWD})
 
 target_link_libraries	(${PROJECT_NAME} PUBLIC SceLibcInternal kernel_sys)
+set(CMAKE_EXE_LINKER_FLAGS "-fuse-ld=lld -v -Xlinker -pie -Xlinker --gc-sections -Xlinker -zmax-page-size=16384 -Xlinker -zcommon-page-size=16384 -Xlinker -T ${CMAKE_CURRENT_SOURCE_DIR}/linker.x -Wl,--build-id=none -Wl,-z,norelro")
+set (CMAKE_C_LINKER_WRAPPER_FLAG "-Xlinker" " ")
 set(CMAKE_EXPORT_COMPILE_COMMANDS ON)