/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-│ │ vi: set et ft=c ts=2 sts=2 sw=2 fenc=utf-8 :vi │ ╞══════════════════════════════════════════════════════════════════════════════╡ │ Copyright 2020 Justine Alexandra Roberts Tunney │ │ │ │ Permission to use, copy, modify, and/or distribute this software for │ │ any purpose with or without fee is hereby granted, provided that the │ │ above copyright notice and this permission notice appear in all copies. │ │ │ │ THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL │ │ WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED │ │ WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE │ │ AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL │ │ DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR │ │ PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER │ │ TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR │ │ PERFORMANCE OF THIS SOFTWARE. │ ╚─────────────────────────────────────────────────────────────────────────────*/ #include "libc/assert.h" #include "libc/atomic.h" #include "libc/calls/calls.h" #include "libc/calls/internal.h" #include "libc/calls/sig.internal.h" #include "libc/calls/struct/sigset.internal.h" #include "libc/calls/syscall-nt.internal.h" #include "libc/errno.h" #include "libc/fmt/itoa.h" #include "libc/intrin/dll.h" #include "libc/intrin/fds.h" #include "libc/intrin/kprintf.h" #include "libc/intrin/strace.h" #include "libc/mem/mem.h" #include "libc/nt/accounting.h" #include "libc/nt/enum/processaccess.h" #include "libc/nt/enum/startf.h" #include "libc/nt/enum/status.h" #include "libc/nt/errors.h" #include "libc/nt/files.h" #include "libc/nt/process.h" #include "libc/nt/runtime.h" #include "libc/nt/struct/processinformation.h" #include "libc/nt/struct/startupinfo.h" #include "libc/nt/synchronization.h" #include "libc/nt/thread.h" #include "libc/nt/thunk/msabi.h" #include "libc/proc/describefds.internal.h" #include "libc/proc/ntspawn.h" #include "libc/runtime/internal.h" #include "libc/str/str.h" #include "libc/sysv/consts/at.h" #include "libc/sysv/consts/o.h" #include "libc/sysv/consts/sig.h" #include "libc/sysv/errfuns.h" #include "libc/thread/posixthread.internal.h" #include "libc/thread/thread.h" #ifdef __x86_64__ __msabi extern typeof(CloseHandle) *const __imp_CloseHandle; __msabi extern typeof(TerminateProcess) *const __imp_TerminateProcess; extern atomic_int __sig_worker_state; static void sys_execve_nt_abort(sigset_t sigmask) { __sig_worker_state &= ~2; __sig_unblock(sigmask); } textwindows int sys_execve_nt(const char *program, char *const argv[], char *const envp[]) { // execve() needs to be @asyncsignalsafe sigset_t sigmask = __sig_block(); __sig_worker_state |= 2; for (;;) if (__sig_worker_state & 1) break; // new process should be a child of our parent int64_t hParentProcess = sys_getppid_nt_win32 ? OpenProcess(kNtProcessDupHandle | kNtProcessCreateProcess, false, sys_getppid_nt_win32) : 0; // inherit pid char pidvar[11 + 21]; FormatUint64(stpcpy(pidvar, "_COSMO_PID="), __pid); // inherit signal mask char maskvar[6 + 21]; FormatUint64(stpcpy(maskvar, "_MASK="), sigmask); // inherit parent process id char ppidvar[12 + 21 + 1 + 21 + 1], *p = ppidvar; p = stpcpy(p, "_COSMO_PPID="); if (hParentProcess) { p = FormatUint64(p, sys_getppid_nt_win32); *p++ = ':'; p = FormatUint64(p, __pid); setenv("_COSMO_PPID", ppidvar, true); } // define stdio handles for the spawned subprocess struct NtStartupInfo si = { .cb = sizeof(struct NtStartupInfo), .dwFlags = kNtStartfUsestdhandles, }; for (int fd = 0; fd < 3; ++fd) { if (!__is_cloexec(g_fds.p + fd)) { si.stdiofds[fd] = g_fds.p[fd].handle; } else { si.stdiofds[fd] = -1; } } // which process is responsible for spawning the child? int64_t hCreatorProcess; if (hParentProcess) { hCreatorProcess = hParentProcess; } else { hCreatorProcess = GetCurrentProcess(); } // pass serialized file descriptor table in environment char *fdspec; int64_t *lpExplicitHandles; uint32_t dwExplicitHandleCount; if (!(fdspec = __describe_fds(g_fds.p, g_fds.n, &si, hCreatorProcess, &lpExplicitHandles, &dwExplicitHandleCount))) { if (hParentProcess) __imp_CloseHandle(hParentProcess); sys_execve_nt_abort(sigmask); return -1; } // inherit pending signals atomic_fetch_or_explicit( __sig.process, atomic_load_explicit(&__get_tls()->tib_sigpending, memory_order_acquire), memory_order_release); // launch the process struct NtProcessInformation pi; int rc = ntspawn(&(struct NtSpawnArgs){ AT_FDCWD, program, argv, envp, (char *[]){fdspec, maskvar, pidvar, ppidvar, 0}, 0, 0, hCreatorProcess, lpExplicitHandles, dwExplicitHandleCount, &si, &pi}); __undescribe_fds(hCreatorProcess, lpExplicitHandles, dwExplicitHandleCount); if (rc == -1) { free(fdspec); if (hParentProcess) __imp_CloseHandle(hParentProcess); sys_execve_nt_abort(sigmask); if (GetLastError() == kNtErrorSharingViolation) { return etxtbsy(); } else { return -1; } } // check if parent spoofing worked if (hParentProcess) { // give child to libc/proc/proc.c worker thread in parent int64_t handle; if (DuplicateHandle(GetCurrentProcess(), pi.hProcess, hParentProcess, &handle, 0, false, kNtDuplicateSameAccess)) { unassert(!(handle & 0xFFFFFFFFFF000000)); __imp_TerminateProcess(-1, 0x23000000u | handle); } else { // TODO(jart): Why does `make loc` print this? // kprintf("DuplicateHandle failed w/ %d\n", GetLastError()); __imp_TerminateProcess(-1, ECHILD); } __builtin_unreachable(); } // we couldn't reparent the new process STRACE("warning: execve() lingering due to non-cosmo parent process"); // terminate other threads _pthread_lock(); struct Dll *e; struct PosixThread *me = _pthread_self(); for (e = dll_first(_pthread_list); e; e = dll_next(_pthread_list, e)) { struct PosixThread *pt = POSIXTHREAD_CONTAINER(e); if (pt == me) continue; TerminateThread( atomic_load_explicit(&pt->tib->tib_syshand, memory_order_relaxed), SIGKILL); } // wait for child to terminate and propagate exit code for (;;) { uint32_t status; WaitForSingleObject(pi.hProcess, -1u); GetExitCodeProcess(pi.hProcess, &status); if (status != kNtStillActive) { if ((status & 0xFF000000u) == 0x23000000u) { // handle child execve() __imp_CloseHandle(pi.hProcess); pi.hProcess = status & 0x00FFFFFF; } else { // handle child _Exit() if (status == 0xc9af3d51u) status = kNtStillActive; TerminateThisProcess(status); } } } } #endif /* __x86_64__ */