/* Internal interfaces for the Windows code Copyright (C) 1995-2022 Free Software Foundation, Inc. This file is part of GDB. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . */ #include "gdbsupport/common-defs.h" #include "nat/windows-nat.h" #include "gdbsupport/common-debug.h" #include "target/target.h" #undef GetModuleFileNameEx #ifndef __CYGWIN__ #define GetModuleFileNameEx GetModuleFileNameExA #else #include #define __USEWIDE #define GetModuleFileNameEx GetModuleFileNameExW #endif namespace windows_nat { /* The most recent event from WaitForDebugEvent. Unlike current_event, this is guaranteed never to come from a pending stop. This is important because only data from the most recent event from WaitForDebugEvent can be used when calling ContinueDebugEvent. */ static DEBUG_EVENT last_wait_event; AdjustTokenPrivileges_ftype *AdjustTokenPrivileges; DebugActiveProcessStop_ftype *DebugActiveProcessStop; DebugBreakProcess_ftype *DebugBreakProcess; DebugSetProcessKillOnExit_ftype *DebugSetProcessKillOnExit; EnumProcessModules_ftype *EnumProcessModules; #ifdef __x86_64__ EnumProcessModulesEx_ftype *EnumProcessModulesEx; #endif GetModuleInformation_ftype *GetModuleInformation; GetModuleFileNameExA_ftype *GetModuleFileNameExA; GetModuleFileNameExW_ftype *GetModuleFileNameExW; LookupPrivilegeValueA_ftype *LookupPrivilegeValueA; OpenProcessToken_ftype *OpenProcessToken; GetCurrentConsoleFont_ftype *GetCurrentConsoleFont; GetConsoleFontSize_ftype *GetConsoleFontSize; #ifdef __x86_64__ Wow64SuspendThread_ftype *Wow64SuspendThread; Wow64GetThreadContext_ftype *Wow64GetThreadContext; Wow64SetThreadContext_ftype *Wow64SetThreadContext; Wow64GetThreadSelectorEntry_ftype *Wow64GetThreadSelectorEntry; #endif GenerateConsoleCtrlEvent_ftype *GenerateConsoleCtrlEvent; #define GetThreadDescription dyn_GetThreadDescription typedef HRESULT WINAPI (GetThreadDescription_ftype) (HANDLE, PWSTR *); static GetThreadDescription_ftype *GetThreadDescription; InitializeProcThreadAttributeList_ftype *InitializeProcThreadAttributeList; UpdateProcThreadAttribute_ftype *UpdateProcThreadAttribute; DeleteProcThreadAttributeList_ftype *DeleteProcThreadAttributeList; /* Note that 'debug_events' must be locally defined in the relevant functions. */ #define DEBUG_EVENTS(fmt, ...) \ debug_prefixed_printf_cond (debug_events, "windows events", fmt, \ ## __VA_ARGS__) void windows_thread_info::suspend () { if (suspended != 0) return; if (SuspendThread (h) == (DWORD) -1) { DWORD err = GetLastError (); /* We get Access Denied (5) when trying to suspend threads that Windows started on behalf of the debuggee, usually when those threads are just about to exit. We can get Invalid Handle (6) if the main thread has exited. */ if (err != ERROR_INVALID_HANDLE && err != ERROR_ACCESS_DENIED) warning (_("SuspendThread (tid=0x%x) failed. (winerr %u: %s)"), (unsigned) tid, (unsigned) err, strwinerror (err)); suspended = -1; } else suspended = 1; } void windows_thread_info::resume () { if (suspended > 0) { stopped_at_software_breakpoint = false; if (ResumeThread (h) == (DWORD) -1) { DWORD err = GetLastError (); warning (_("warning: ResumeThread (tid=0x%x) failed. (winerr %u: %s)"), (unsigned) tid, (unsigned) err, strwinerror (err)); } } suspended = 0; } const char * windows_thread_info::thread_name () { if (GetThreadDescription != nullptr) { PWSTR value; HRESULT result = GetThreadDescription (h, &value); if (SUCCEEDED (result)) { int needed = WideCharToMultiByte (CP_ACP, 0, value, -1, nullptr, 0, nullptr, nullptr); if (needed != 0) { /* USED_DEFAULT is how we detect that the encoding conversion had to fall back to the substitution character. It seems better to just reject bad conversions here. */ BOOL used_default = FALSE; gdb::unique_xmalloc_ptr new_name ((char *) xmalloc (needed)); if (WideCharToMultiByte (CP_ACP, 0, value, -1, new_name.get (), needed, nullptr, &used_default) == needed && !used_default && strlen (new_name.get ()) > 0) name = std::move (new_name); } LocalFree (value); } } return name.get (); } /* Try to determine the executable filename. EXE_NAME_RET is a pointer to a buffer whose size is EXE_NAME_MAX_LEN. Upon success, the filename is stored inside EXE_NAME_RET, and this function returns nonzero. Otherwise, this function returns zero and the contents of EXE_NAME_RET is undefined. */ int windows_process_info::get_exec_module_filename (char *exe_name_ret, size_t exe_name_max_len) { DWORD len; HMODULE dh_buf; DWORD cbNeeded; cbNeeded = 0; #ifdef __x86_64__ if (wow64_process) { if (!EnumProcessModulesEx (handle, &dh_buf, sizeof (HMODULE), &cbNeeded, LIST_MODULES_32BIT) || !cbNeeded) return 0; } else #endif { if (!EnumProcessModules (handle, &dh_buf, sizeof (HMODULE), &cbNeeded) || !cbNeeded) return 0; } /* We know the executable is always first in the list of modules, which we just fetched. So no need to fetch more. */ #ifdef __CYGWIN__ { /* Cygwin prefers that the path be in /x/y/z format, so extract the filename into a temporary buffer first, and then convert it to POSIX format into the destination buffer. */ wchar_t *pathbuf = (wchar_t *) alloca (exe_name_max_len * sizeof (wchar_t)); len = GetModuleFileNameEx (handle, dh_buf, pathbuf, exe_name_max_len); if (len == 0) { unsigned err = (unsigned) GetLastError (); error (_("Error getting executable filename (error %u): %s"), err, strwinerror (err)); } if (cygwin_conv_path (CCP_WIN_W_TO_POSIX, pathbuf, exe_name_ret, exe_name_max_len) < 0) error (_("Error converting executable filename to POSIX: %d."), errno); } #else len = GetModuleFileNameEx (handle, dh_buf, exe_name_ret, exe_name_max_len); if (len == 0) { unsigned err = (unsigned) GetLastError (); error (_("Error getting executable filename (error %u): %s"), err, strwinerror (err)); } #endif return 1; /* success */ } const char * windows_process_info::pid_to_exec_file (int pid) { static char path[MAX_PATH]; #ifdef __CYGWIN__ /* Try to find exe name as symlink target of /proc//exe. */ int nchars; char procexe[sizeof ("/proc/4294967295/exe")]; xsnprintf (procexe, sizeof (procexe), "/proc/%u/exe", pid); nchars = readlink (procexe, path, sizeof(path)); if (nchars > 0 && nchars < sizeof (path)) { path[nchars] = '\0'; /* Got it */ return path; } #endif /* If we get here then either Cygwin is hosed, this isn't a Cygwin version of gdb, or we're trying to debug a non-Cygwin windows executable. */ if (!get_exec_module_filename (path, sizeof (path))) path[0] = '\0'; return path; } /* Return the name of the DLL referenced by H at ADDRESS. UNICODE determines what sort of string is read from the inferior. Returns the name of the DLL, or NULL on error. If a name is returned, it is stored in a static buffer which is valid until the next call to get_image_name. */ static const char * get_image_name (HANDLE h, void *address, int unicode) { #ifdef __CYGWIN__ static char buf[MAX_PATH]; #else static char buf[(2 * MAX_PATH) + 1]; #endif DWORD size = unicode ? sizeof (WCHAR) : sizeof (char); char *address_ptr; int len = 0; char b[2]; SIZE_T done; /* Attempt to read the name of the dll that was detected. This is documented to work only when actively debugging a program. It will not work for attached processes. */ if (address == NULL) return NULL; /* See if we could read the address of a string, and that the address isn't null. */ if (!ReadProcessMemory (h, address, &address_ptr, sizeof (address_ptr), &done) || done != sizeof (address_ptr) || !address_ptr) return NULL; /* Find the length of the string. */ while (ReadProcessMemory (h, address_ptr + len++ * size, &b, size, &done) && (b[0] != 0 || b[size - 1] != 0) && done == size) continue; if (!unicode) ReadProcessMemory (h, address_ptr, buf, len, &done); else { WCHAR *unicode_address = (WCHAR *) alloca (len * sizeof (WCHAR)); ReadProcessMemory (h, address_ptr, unicode_address, len * sizeof (WCHAR), &done); #ifdef __CYGWIN__ wcstombs (buf, unicode_address, MAX_PATH); #else WideCharToMultiByte (CP_ACP, 0, unicode_address, len, buf, sizeof buf, 0, 0); #endif } return buf; } /* See nat/windows-nat.h. */ bool windows_process_info::handle_ms_vc_exception (const EXCEPTION_RECORD *rec) { if (rec->NumberParameters >= 3 && (rec->ExceptionInformation[0] & 0xffffffff) == 0x1000) { DWORD named_thread_id; windows_thread_info *named_thread; CORE_ADDR thread_name_target; thread_name_target = rec->ExceptionInformation[1]; named_thread_id = (DWORD) (0xffffffff & rec->ExceptionInformation[2]); if (named_thread_id == (DWORD) -1) named_thread_id = current_event.dwThreadId; named_thread = thread_rec (ptid_t (current_event.dwProcessId, named_thread_id, 0), DONT_INVALIDATE_CONTEXT); if (named_thread != NULL) { int thread_name_len; gdb::unique_xmalloc_ptr thread_name = target_read_string (thread_name_target, 1025, &thread_name_len); if (thread_name_len > 0) { thread_name.get ()[thread_name_len - 1] = '\0'; named_thread->name = std::move (thread_name); } } return true; } return false; } /* The exception thrown by a program to tell the debugger the name of a thread. The exception record contains an ID of a thread and a name to give it. This exception has no documented name, but MSDN dubs it "MS_VC_EXCEPTION" in one code example. */ #define MS_VC_EXCEPTION 0x406d1388 handle_exception_result windows_process_info::handle_exception (struct target_waitstatus *ourstatus, bool debug_exceptions) { #define DEBUG_EXCEPTION_SIMPLE(x) if (debug_exceptions) \ debug_printf ("gdb: Target exception %s at %s\n", x, \ host_address_to_string (\ current_event.u.Exception.ExceptionRecord.ExceptionAddress)) EXCEPTION_RECORD *rec = ¤t_event.u.Exception.ExceptionRecord; DWORD code = rec->ExceptionCode; handle_exception_result result = HANDLE_EXCEPTION_HANDLED; memcpy (&siginfo_er, rec, sizeof siginfo_er); /* Record the context of the current thread. */ thread_rec (ptid_t (current_event.dwProcessId, current_event.dwThreadId, 0), DONT_SUSPEND); last_sig = GDB_SIGNAL_0; switch (code) { case EXCEPTION_ACCESS_VIOLATION: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ACCESS_VIOLATION"); ourstatus->set_stopped (GDB_SIGNAL_SEGV); if (handle_access_violation (rec)) return HANDLE_EXCEPTION_UNHANDLED; break; case STATUS_STACK_OVERFLOW: DEBUG_EXCEPTION_SIMPLE ("STATUS_STACK_OVERFLOW"); ourstatus->set_stopped (GDB_SIGNAL_SEGV); break; case STATUS_FLOAT_DENORMAL_OPERAND: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_DENORMAL_OPERAND"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case EXCEPTION_ARRAY_BOUNDS_EXCEEDED: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ARRAY_BOUNDS_EXCEEDED"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_INEXACT_RESULT: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_INEXACT_RESULT"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_INVALID_OPERATION: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_INVALID_OPERATION"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_OVERFLOW: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_OVERFLOW"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_STACK_CHECK: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_STACK_CHECK"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_UNDERFLOW: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_UNDERFLOW"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_FLOAT_DIVIDE_BY_ZERO: DEBUG_EXCEPTION_SIMPLE ("STATUS_FLOAT_DIVIDE_BY_ZERO"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_INTEGER_DIVIDE_BY_ZERO: DEBUG_EXCEPTION_SIMPLE ("STATUS_INTEGER_DIVIDE_BY_ZERO"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case STATUS_INTEGER_OVERFLOW: DEBUG_EXCEPTION_SIMPLE ("STATUS_INTEGER_OVERFLOW"); ourstatus->set_stopped (GDB_SIGNAL_FPE); break; case EXCEPTION_BREAKPOINT: #ifdef __x86_64__ if (ignore_first_breakpoint) { /* For WOW64 processes, there are always 2 breakpoint exceptions on startup, first a BREAKPOINT for the 64bit ntdll.dll, then a WX86_BREAKPOINT for the 32bit ntdll.dll. Here we only care about the WX86_BREAKPOINT's. */ DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT - ignore_first_breakpoint"); ourstatus->set_spurious (); ignore_first_breakpoint = false; break; } else if (wow64_process) { /* This breakpoint exception is triggered for WOW64 processes when reaching an int3 instruction in 64bit code. gdb checks for int3 in case of SIGTRAP, this fails because Wow64GetThreadContext can only report the pc of 32bit code, and gdb lets the target process continue. So handle it as SIGINT instead, then the target is stopped unconditionally. */ DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT - wow64_process"); rec->ExceptionCode = DBG_CONTROL_C; ourstatus->set_stopped (GDB_SIGNAL_INT); break; } #endif /* FALLTHROUGH */ case STATUS_WX86_BREAKPOINT: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_BREAKPOINT"); ourstatus->set_stopped (GDB_SIGNAL_TRAP); break; case DBG_CONTROL_C: DEBUG_EXCEPTION_SIMPLE ("DBG_CONTROL_C"); ourstatus->set_stopped (GDB_SIGNAL_INT); break; case DBG_CONTROL_BREAK: DEBUG_EXCEPTION_SIMPLE ("DBG_CONTROL_BREAK"); ourstatus->set_stopped (GDB_SIGNAL_INT); break; case EXCEPTION_SINGLE_STEP: case STATUS_WX86_SINGLE_STEP: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_SINGLE_STEP"); ourstatus->set_stopped (GDB_SIGNAL_TRAP); break; case EXCEPTION_ILLEGAL_INSTRUCTION: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_ILLEGAL_INSTRUCTION"); ourstatus->set_stopped (GDB_SIGNAL_ILL); break; case EXCEPTION_PRIV_INSTRUCTION: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_PRIV_INSTRUCTION"); ourstatus->set_stopped (GDB_SIGNAL_ILL); break; case EXCEPTION_NONCONTINUABLE_EXCEPTION: DEBUG_EXCEPTION_SIMPLE ("EXCEPTION_NONCONTINUABLE_EXCEPTION"); ourstatus->set_stopped (GDB_SIGNAL_ILL); break; case MS_VC_EXCEPTION: DEBUG_EXCEPTION_SIMPLE ("MS_VC_EXCEPTION"); if (handle_ms_vc_exception (rec)) { ourstatus->set_stopped (GDB_SIGNAL_TRAP); result = HANDLE_EXCEPTION_IGNORED; break; } /* treat improperly formed exception as unknown */ /* FALLTHROUGH */ default: /* Treat unhandled first chance exceptions specially. */ if (current_event.u.Exception.dwFirstChance) return HANDLE_EXCEPTION_UNHANDLED; debug_printf ("gdb: unknown target exception 0x%08x at %s\n", (unsigned) current_event.u.Exception.ExceptionRecord.ExceptionCode, host_address_to_string ( current_event.u.Exception.ExceptionRecord.ExceptionAddress)); ourstatus->set_stopped (GDB_SIGNAL_UNKNOWN); break; } if (ourstatus->kind () == TARGET_WAITKIND_STOPPED) last_sig = ourstatus->sig (); return result; #undef DEBUG_EXCEPTION_SIMPLE } /* See nat/windows-nat.h. */ void windows_process_info::add_dll (LPVOID load_addr) { HMODULE dummy_hmodule; DWORD cb_needed; HMODULE *hmodules; int i; #ifdef __x86_64__ if (wow64_process) { if (EnumProcessModulesEx (handle, &dummy_hmodule, sizeof (HMODULE), &cb_needed, LIST_MODULES_32BIT) == 0) return; } else #endif { if (EnumProcessModules (handle, &dummy_hmodule, sizeof (HMODULE), &cb_needed) == 0) return; } if (cb_needed < 1) return; hmodules = (HMODULE *) alloca (cb_needed); #ifdef __x86_64__ if (wow64_process) { if (EnumProcessModulesEx (handle, hmodules, cb_needed, &cb_needed, LIST_MODULES_32BIT) == 0) return; } else #endif { if (EnumProcessModules (handle, hmodules, cb_needed, &cb_needed) == 0) return; } char system_dir[MAX_PATH]; char syswow_dir[MAX_PATH]; size_t system_dir_len = 0; bool convert_syswow_dir = false; #ifdef __x86_64__ if (wow64_process) #endif { /* This fails on 32bit Windows because it has no SysWOW64 directory, and in this case a path conversion isn't necessary. */ UINT len = GetSystemWow64DirectoryA (syswow_dir, sizeof (syswow_dir)); if (len > 0) { /* Check that we have passed a large enough buffer. */ gdb_assert (len < sizeof (syswow_dir)); len = GetSystemDirectoryA (system_dir, sizeof (system_dir)); /* Error check. */ gdb_assert (len != 0); /* Check that we have passed a large enough buffer. */ gdb_assert (len < sizeof (system_dir)); strcat (system_dir, "\\"); strcat (syswow_dir, "\\"); system_dir_len = strlen (system_dir); convert_syswow_dir = true; } } for (i = 1; i < (int) (cb_needed / sizeof (HMODULE)); i++) { MODULEINFO mi; #ifdef __USEWIDE wchar_t dll_name[MAX_PATH]; char dll_name_mb[MAX_PATH]; #else char dll_name[MAX_PATH]; #endif const char *name; if (GetModuleInformation (handle, hmodules[i], &mi, sizeof (mi)) == 0) continue; if (GetModuleFileNameEx (handle, hmodules[i], dll_name, sizeof (dll_name)) == 0) continue; #ifdef __USEWIDE wcstombs (dll_name_mb, dll_name, MAX_PATH); name = dll_name_mb; #else name = dll_name; #endif /* Convert the DLL path of 32bit processes returned by GetModuleFileNameEx from the 64bit system directory to the 32bit syswow64 directory if necessary. */ std::string syswow_dll_path; if (convert_syswow_dir && strncasecmp (name, system_dir, system_dir_len) == 0 && strchr (name + system_dir_len, '\\') == nullptr) { syswow_dll_path = syswow_dir; syswow_dll_path += name + system_dir_len; name = syswow_dll_path.c_str(); } /* Record the DLL if either LOAD_ADDR is NULL or the address at which the DLL was loaded is equal to LOAD_ADDR. */ if (!(load_addr != nullptr && mi.lpBaseOfDll != load_addr)) { handle_load_dll (name, mi.lpBaseOfDll); if (load_addr != nullptr) return; } } } /* See nat/windows-nat.h. */ void windows_process_info::dll_loaded_event () { gdb_assert (current_event.dwDebugEventCode == LOAD_DLL_DEBUG_EVENT); LOAD_DLL_DEBUG_INFO *event = ¤t_event.u.LoadDll; const char *dll_name; /* Try getting the DLL name via the lpImageName field of the event. Note that Microsoft documents this fields as strictly optional, in the sense that it might be NULL. And the first DLL event in particular is explicitly documented as "likely not pass[ed]" (source: MSDN LOAD_DLL_DEBUG_INFO structure). */ dll_name = get_image_name (handle, event->lpImageName, event->fUnicode); /* If the DLL name could not be gleaned via lpImageName, try harder by enumerating all the DLLs loaded into the inferior, looking for one that is loaded at base address = lpBaseOfDll. */ if (dll_name != nullptr) handle_load_dll (dll_name, event->lpBaseOfDll); else if (event->lpBaseOfDll != nullptr) add_dll (event->lpBaseOfDll); } /* See nat/windows-nat.h. */ void windows_process_info::add_all_dlls () { add_dll (nullptr); } /* See nat/windows-nat.h. */ bool windows_process_info::matching_pending_stop (bool debug_events) { /* If there are pending stops, and we might plausibly hit one of them, we don't want to actually continue the inferior -- we just want to report the stop. In this case, we just pretend to continue. See the comment by the definition of "pending_stops" for details on why this is needed. */ for (const auto &item : pending_stops) { if (desired_stop_thread_id == -1 || desired_stop_thread_id == item.thread_id) { DEBUG_EVENTS ("pending stop anticipated, desired=0x%x, item=0x%x", desired_stop_thread_id, item.thread_id); return true; } } return false; } /* See nat/windows-nat.h. */ gdb::optional windows_process_info::fetch_pending_stop (bool debug_events) { gdb::optional result; for (auto iter = pending_stops.begin (); iter != pending_stops.end (); ++iter) { if (desired_stop_thread_id == -1 || desired_stop_thread_id == iter->thread_id) { result = *iter; current_event = iter->event; DEBUG_EVENTS ("pending stop found in 0x%x (desired=0x%x)", iter->thread_id, desired_stop_thread_id); pending_stops.erase (iter); break; } } return result; } /* See nat/windows-nat.h. */ BOOL continue_last_debug_event (DWORD continue_status, bool debug_events) { DEBUG_EVENTS ("ContinueDebugEvent (cpid=%d, ctid=0x%x, %s)", (unsigned) last_wait_event.dwProcessId, (unsigned) last_wait_event.dwThreadId, continue_status == DBG_CONTINUE ? "DBG_CONTINUE" : "DBG_EXCEPTION_NOT_HANDLED"); return ContinueDebugEvent (last_wait_event.dwProcessId, last_wait_event.dwThreadId, continue_status); } /* See nat/windows-nat.h. */ BOOL wait_for_debug_event (DEBUG_EVENT *event, DWORD timeout) { BOOL result = WaitForDebugEvent (event, timeout); if (result) last_wait_event = *event; return result; } /* Flags to pass to UpdateProcThreadAttribute. */ #define relocate_aslr_flags ((0x2 << 8) | (0x2 << 16)) /* Attribute to pass to UpdateProcThreadAttribute. */ #define mitigation_policy 0x00020007 /* Pick one of the symbols as a sentinel. */ #ifdef PROCESS_CREATION_MITIGATION_POLICY_FORCE_RELOCATE_IMAGES_ALWAYS_OFF static_assert ((PROCESS_CREATION_MITIGATION_POLICY_FORCE_RELOCATE_IMAGES_ALWAYS_OFF | PROCESS_CREATION_MITIGATION_POLICY_BOTTOM_UP_ASLR_ALWAYS_OFF) == relocate_aslr_flags, "check that ASLR flag values are correct"); static_assert (PROC_THREAD_ATTRIBUTE_MITIGATION_POLICY == mitigation_policy, "check that mitigation policy value is correct"); #endif /* Helper template for the CreateProcess wrappers. FUNC is the type of the underlying CreateProcess call. CHAR is the character type to use, and INFO is the "startupinfo" type to use. DO_CREATE_PROCESS is the underlying CreateProcess function to use; the remaining arguments are passed to it. */ template BOOL create_process_wrapper (FUNC *do_create_process, const CHAR *image, CHAR *command_line, DWORD flags, void *environment, const CHAR *cur_dir, bool no_randomization, INFO *startup_info, PROCESS_INFORMATION *process_info) { if (no_randomization && disable_randomization_available ()) { static bool tried_and_failed; if (!tried_and_failed) { /* Windows 8 is required for the real declaration, but to allow building on earlier versions of Windows, we declare the type locally. */ struct gdb_extended_info { INFO StartupInfo; gdb_lpproc_thread_attribute_list lpAttributeList; }; gdb_extended_info info_ex {}; if (startup_info != nullptr) info_ex.StartupInfo = *startup_info; info_ex.StartupInfo.cb = sizeof (info_ex); SIZE_T size = 0; /* Ignore the result here. The documentation says the first call always fails, by design. */ InitializeProcThreadAttributeList (nullptr, 1, 0, &size); info_ex.lpAttributeList = (PPROC_THREAD_ATTRIBUTE_LIST) alloca (size); InitializeProcThreadAttributeList (info_ex.lpAttributeList, 1, 0, &size); gdb::optional return_value; DWORD attr_flags = relocate_aslr_flags; if (!UpdateProcThreadAttribute (info_ex.lpAttributeList, 0, mitigation_policy, &attr_flags, sizeof (attr_flags), nullptr, nullptr)) tried_and_failed = true; else { BOOL result = do_create_process (image, command_line, nullptr, nullptr, TRUE, (flags | EXTENDED_STARTUPINFO_PRESENT), environment, cur_dir, (STARTUPINFO *) &info_ex, process_info); if (result) return_value = result; else if (GetLastError () == ERROR_INVALID_PARAMETER) tried_and_failed = true; else return_value = FALSE; } DeleteProcThreadAttributeList (info_ex.lpAttributeList); if (return_value.has_value ()) return *return_value; } } return do_create_process (image, command_line, /* command line */ nullptr, /* Security */ nullptr, /* thread */ TRUE, /* inherit handles */ flags, /* start flags */ environment, /* environment */ cur_dir, /* current directory */ startup_info, process_info); } /* See nat/windows-nat.h. */ BOOL create_process (const char *image, char *command_line, DWORD flags, void *environment, const char *cur_dir, bool no_randomization, STARTUPINFOA *startup_info, PROCESS_INFORMATION *process_info) { return create_process_wrapper (CreateProcessA, image, command_line, flags, environment, cur_dir, no_randomization, startup_info, process_info); } #ifdef __CYGWIN__ /* See nat/windows-nat.h. */ BOOL create_process (const wchar_t *image, wchar_t *command_line, DWORD flags, void *environment, const wchar_t *cur_dir, bool no_randomization, STARTUPINFOW *startup_info, PROCESS_INFORMATION *process_info) { return create_process_wrapper (CreateProcessW, image, command_line, flags, environment, cur_dir, no_randomization, startup_info, process_info); } #endif /* __CYGWIN__ */ /* Define dummy functions which always return error for the rare cases where these functions could not be found. */ template BOOL WINAPI bad (T... args) { return FALSE; } template DWORD WINAPI bad (T... args) { return 0; } static BOOL WINAPI bad_GetCurrentConsoleFont (HANDLE w, BOOL bMaxWindow, CONSOLE_FONT_INFO *f) { f->nFont = 0; return 1; } static COORD WINAPI bad_GetConsoleFontSize (HANDLE w, DWORD nFont) { COORD size; size.X = 8; size.Y = 12; return size; } /* See windows-nat.h. */ bool disable_randomization_available () { return (InitializeProcThreadAttributeList != nullptr && UpdateProcThreadAttribute != nullptr && DeleteProcThreadAttributeList != nullptr); } /* See windows-nat.h. */ bool initialize_loadable () { bool result = true; HMODULE hm = NULL; #define GPA(m, func) \ func = (func ## _ftype *) GetProcAddress (m, #func) hm = LoadLibrary (TEXT ("kernel32.dll")); if (hm) { GPA (hm, DebugActiveProcessStop); GPA (hm, DebugBreakProcess); GPA (hm, DebugSetProcessKillOnExit); GPA (hm, GetConsoleFontSize); GPA (hm, DebugActiveProcessStop); GPA (hm, GetCurrentConsoleFont); #ifdef __x86_64__ GPA (hm, Wow64SuspendThread); GPA (hm, Wow64GetThreadContext); GPA (hm, Wow64SetThreadContext); GPA (hm, Wow64GetThreadSelectorEntry); #endif GPA (hm, GenerateConsoleCtrlEvent); GPA (hm, GetThreadDescription); GPA (hm, InitializeProcThreadAttributeList); GPA (hm, UpdateProcThreadAttribute); GPA (hm, DeleteProcThreadAttributeList); } /* Set variables to dummy versions of these processes if the function wasn't found in kernel32.dll. */ if (!DebugBreakProcess) DebugBreakProcess = bad; if (!DebugActiveProcessStop || !DebugSetProcessKillOnExit) { DebugActiveProcessStop = bad; DebugSetProcessKillOnExit = bad; } if (!GetConsoleFontSize) GetConsoleFontSize = bad_GetConsoleFontSize; if (!GetCurrentConsoleFont) GetCurrentConsoleFont = bad_GetCurrentConsoleFont; /* Load optional functions used for retrieving filename information associated with the currently debugged process or its dlls. */ hm = LoadLibrary (TEXT ("psapi.dll")); if (hm) { GPA (hm, EnumProcessModules); #ifdef __x86_64__ GPA (hm, EnumProcessModulesEx); #endif GPA (hm, GetModuleInformation); GPA (hm, GetModuleFileNameExA); GPA (hm, GetModuleFileNameExW); } if (!EnumProcessModules || !GetModuleInformation || !GetModuleFileNameExA || !GetModuleFileNameExW) { /* Set variables to dummy versions of these processes if the function wasn't found in psapi.dll. */ EnumProcessModules = bad; GetModuleInformation = bad; GetModuleFileNameExA = bad; GetModuleFileNameExW = bad; result = false; } hm = LoadLibrary (TEXT ("advapi32.dll")); if (hm) { GPA (hm, OpenProcessToken); GPA (hm, LookupPrivilegeValueA); GPA (hm, AdjustTokenPrivileges); /* Only need to set one of these since if OpenProcessToken fails nothing else is needed. */ if (!OpenProcessToken || !LookupPrivilegeValueA || !AdjustTokenPrivileges) OpenProcessToken = bad; } /* On some versions of Windows, this function is only available in KernelBase.dll, not kernel32.dll. */ if (GetThreadDescription == nullptr) { hm = LoadLibrary (TEXT ("KernelBase.dll")); if (hm) GPA (hm, GetThreadDescription); } #undef GPA return result; } }