termux-packages/packages/ninja/src-spawn.cc.patch

diff --git a/src/spawn.cc b/src/spawn.cc
new file mode 100644
index 0000000..1eed715
--- /dev/null
+++ b/src/spawn.cc
@@ -0,0 +1,381 @@
+/*
+ * Copyright (C) 2017 The Android Open Source Project
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *  * Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *  * Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+ * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+ * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+ * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+ * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+ * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <signal.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include <android/fdsan.h>
+
+#include "spawn.h"
+
+// Bionic "private/ScopedSignalBlocker.h" + one macro needed
+#define BIONIC_DISALLOW_COPY_AND_ASSIGN(TypeName) \
+  TypeName(const TypeName&) = delete;             \
+    void operator=(const TypeName&) = delete
+
+class ScopedSignalBlocker {
+ public:
+  // Block all signals.
+  explicit ScopedSignalBlocker() {
+    sigset_t set;
+    sigfillset(&set);
+    sigprocmask(SIG_BLOCK, &set, &old_set_);
+  }
+
+  // Block just the specified signal.
+  explicit ScopedSignalBlocker(int signal) {
+    sigset_t set = {};
+    sigaddset(&set, signal);
+    sigprocmask(SIG_BLOCK, &set, &old_set_);
+  }
+
+  ~ScopedSignalBlocker() {
+    reset();
+  }
+
+  void reset() {
+    sigprocmask(SIG_SETMASK, &old_set_, nullptr);
+  }
+
+  sigset_t old_set_;
+
+  BIONIC_DISALLOW_COPY_AND_ASSIGN(ScopedSignalBlocker);
+};
+
+// Bionic "private/SigSetConverter.h"
+union SigSetConverter {
+  int bsd;
+  sigset_t sigset;
+  sigset64_t sigset64;
+};
+
+enum Action {
+  kOpen,
+  kClose,
+  kDup2
+};
+
+struct __posix_spawn_file_action {
+  __posix_spawn_file_action* next;
+
+  Action what;
+  int fd;
+  int new_fd;
+  char* path;
+  int flags;
+  mode_t mode;
+
+  void Do() {
+    if (what == kOpen) {
+      fd = open(path, flags, mode);
+      if (fd == -1) _exit(127);
+      // If it didn't land where we wanted it, move it.
+      if (fd != new_fd) {
+        if (dup2(fd, new_fd) == -1) _exit(127);
+        close(fd);
+      }
+    } else if (what == kClose) {
+      // Failure to close is ignored.
+      close(fd);
+    } else {
+      if (dup2(fd, new_fd) == -1) _exit(127);
+    }
+  }
+};
+
+struct __posix_spawn_file_actions {
+  __posix_spawn_file_action* head;
+  __posix_spawn_file_action* last;
+
+  void Do() {
+    for (__posix_spawn_file_action* action = head; action != nullptr; action = action->next) {
+      action->Do();
+    }
+  }
+};
+
+struct __posix_spawnattr {
+  short flags;
+  pid_t pgroup;
+  sched_param schedparam;
+  int schedpolicy;
+  SigSetConverter sigmask;
+  SigSetConverter sigdefault;
+};
+
+static void ApplyAttrs(short flags, const posix_spawnattr_t* attr) {
+  // POSIX: "If POSIX_SPAWN_SETSIGDEF is set ... signals in sigdefault ...
+  // shall be set to their default actions in the child process."
+  // POSIX: "Signals set to be caught by the calling process shall be
+  // set to the default action in the child process."
+  bool use_sigdefault = ((flags & POSIX_SPAWN_SETSIGDEF) != 0);
+  const struct sigaction default_sa = { .sa_handler = SIG_DFL };
+  for (int s = 1; s < _NSIG; ++s) {
+    bool reset = false;
+    if (use_sigdefault && sigismember(&(*attr)->sigdefault.sigset, s)) {
+      reset = true;
+    } else {
+      struct sigaction current;
+      if (sigaction(s, nullptr, &current) == -1) _exit(127);
+      reset = (current.sa_handler != SIG_IGN && current.sa_handler != SIG_DFL);
+    }
+    if (reset && sigaction(s, &default_sa, nullptr) == -1) _exit(127);
+  }
+
+  if ((flags & POSIX_SPAWN_SETPGROUP) != 0 && setpgid(0, (*attr)->pgroup) == -1) _exit(127);
+  if ((flags & POSIX_SPAWN_SETSID) != 0 && setsid() == -1) _exit(127);
+
+  // POSIX_SPAWN_SETSCHEDULER overrides POSIX_SPAWN_SETSCHEDPARAM, but it is not an error
+  // to set both.
+  if ((flags & POSIX_SPAWN_SETSCHEDULER) != 0) {
+    if (sched_setscheduler(0, (*attr)->schedpolicy, &(*attr)->schedparam) == -1) _exit(127);
+  } else if ((flags & POSIX_SPAWN_SETSCHEDPARAM) != 0) {
+    if (sched_setparam(0, &(*attr)->schedparam) == -1) _exit(127);
+  }
+
+  if ((flags & POSIX_SPAWN_RESETIDS) != 0) {
+    if (seteuid(getuid()) == -1 || setegid(getgid()) == -1) _exit(127);
+  }
+
+  if ((flags & POSIX_SPAWN_SETSIGMASK) != 0) {
+    if (sigprocmask(SIG_SETMASK, &(*attr)->sigmask.sigset, nullptr)) _exit(127);
+  }
+}
+
+static int posix_spawn(pid_t* pid_ptr,
+                       const char* path,
+                       const posix_spawn_file_actions_t* actions,
+                       const posix_spawnattr_t* attr,
+                       char* const argv[],
+                       char* const env[],
+                       int exec_fn(const char* path, char* const argv[], char* const env[])) {
+  // See http://man7.org/linux/man-pages/man3/posix_spawn.3.html
+  // and http://pubs.opengroup.org/onlinepubs/9699919799/functions/posix_spawn.html
+
+  ScopedSignalBlocker ssb;
+
+  short flags = attr ? (*attr)->flags : 0;
+  bool use_vfork = ((flags & POSIX_SPAWN_USEVFORK) != 0) || (actions == nullptr && flags == 0);
+
+  pid_t pid = use_vfork ? vfork() : fork();
+  if (pid == -1) return errno;
+
+  if (pid == 0) {
+    // Child.
+    ApplyAttrs(flags, attr);
+    if (actions) (*actions)->Do();
+    if ((flags & POSIX_SPAWN_SETSIGMASK) == 0) ssb.reset();
+    exec_fn(path, argv, env ? env : environ);
+    _exit(127);
+  }
+
+  // Parent.
+  if (pid_ptr) *pid_ptr = pid;
+  return 0;
+}
+
+int posix_spawn(pid_t* pid, const char* path, const posix_spawn_file_actions_t* actions,
+                const posix_spawnattr_t* attr, char* const argv[], char* const env[]) {
+  return posix_spawn(pid, path, actions, attr, argv, env, execve);
+}
+
+int posix_spawnp(pid_t* pid, const char* file, const posix_spawn_file_actions_t* actions,
+                 const posix_spawnattr_t* attr, char* const argv[], char* const env[]) {
+  return posix_spawn(pid, file, actions, attr, argv, env, execvpe);
+}
+
+int posix_spawnattr_init(posix_spawnattr_t* attr) {
+  *attr = reinterpret_cast<__posix_spawnattr*>(calloc(1, sizeof(__posix_spawnattr)));
+  return (*attr == nullptr) ? errno : 0;
+}
+
+int posix_spawnattr_destroy(posix_spawnattr_t* attr) {
+  free(*attr);
+  *attr = nullptr;
+  return 0;
+}
+
+int posix_spawnattr_setflags(posix_spawnattr_t* attr, short flags) {
+  if ((flags & ~(POSIX_SPAWN_RESETIDS | POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_SETSIGDEF |
+                 POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER |
+                 POSIX_SPAWN_USEVFORK | POSIX_SPAWN_SETSID)) != 0) {
+    return EINVAL;
+  }
+  (*attr)->flags = flags;
+  return 0;
+}
+
+int posix_spawnattr_getflags(const posix_spawnattr_t* attr, short* flags) {
+  *flags = (*attr)->flags;
+  return 0;
+}
+
+int posix_spawnattr_setpgroup(posix_spawnattr_t* attr, pid_t pgroup) {
+  (*attr)->pgroup = pgroup;
+  return 0;
+}
+
+int posix_spawnattr_getpgroup(const posix_spawnattr_t* attr, pid_t* pgroup) {
+  *pgroup = (*attr)->pgroup;
+  return 0;
+}
+
+int posix_spawnattr_setsigmask(posix_spawnattr_t* attr, const sigset_t* mask) {
+  (*attr)->sigmask.sigset = *mask;
+  return 0;
+}
+
+int posix_spawnattr_setsigmask64(posix_spawnattr_t* attr, const sigset64_t* mask) {
+  (*attr)->sigmask.sigset64 = *mask;
+  return 0;
+}
+
+int posix_spawnattr_getsigmask(const posix_spawnattr_t* attr, sigset_t* mask) {
+  *mask = (*attr)->sigmask.sigset;
+  return 0;
+}
+
+int posix_spawnattr_getsigmask64(const posix_spawnattr_t* attr, sigset64_t* mask) {
+  *mask = (*attr)->sigmask.sigset64;
+  return 0;
+}
+
+int posix_spawnattr_setsigdefault(posix_spawnattr_t* attr, const sigset_t* mask) {
+  (*attr)->sigdefault.sigset = *mask;
+  return 0;
+}
+
+int posix_spawnattr_setsigdefault64(posix_spawnattr_t* attr, const sigset64_t* mask) {
+  (*attr)->sigdefault.sigset64 = *mask;
+  return 0;
+}
+
+int posix_spawnattr_getsigdefault(const posix_spawnattr_t* attr, sigset_t* mask) {
+  *mask = (*attr)->sigdefault.sigset;
+  return 0;
+}
+
+int posix_spawnattr_getsigdefault64(const posix_spawnattr_t* attr, sigset64_t* mask) {
+  *mask = (*attr)->sigdefault.sigset64;
+  return 0;
+}
+
+int posix_spawnattr_setschedparam(posix_spawnattr_t* attr, const struct sched_param* param) {
+  (*attr)->schedparam = *param;
+  return 0;
+}
+
+int posix_spawnattr_getschedparam(const posix_spawnattr_t* attr, struct sched_param* param) {
+  *param = (*attr)->schedparam;
+  return 0;
+}
+
+int posix_spawnattr_setschedpolicy(posix_spawnattr_t* attr, int policy) {
+  (*attr)->schedpolicy = policy;
+  return 0;
+}
+
+int posix_spawnattr_getschedpolicy(const posix_spawnattr_t* attr, int* policy) {
+  *policy = (*attr)->schedpolicy;
+  return 0;
+}
+
+int posix_spawn_file_actions_init(posix_spawn_file_actions_t* actions) {
+  *actions = reinterpret_cast<__posix_spawn_file_actions*>(calloc(1, sizeof(**actions)));
+  return (*actions == nullptr) ? errno : 0;
+}
+
+int posix_spawn_file_actions_destroy(posix_spawn_file_actions_t* actions) {
+  __posix_spawn_file_action* a = (*actions)->head;
+  while (a) {
+    __posix_spawn_file_action* last = a;
+    a = a->next;
+    free(last->path);
+    free(last);
+  }
+  free(*actions);
+  *actions = nullptr;
+  return 0;
+}
+
+static int posix_spawn_add_file_action(posix_spawn_file_actions_t* actions,
+                                       Action what,
+                                       int fd,
+                                       int new_fd,
+                                       const char* path,
+                                       int flags,
+                                       mode_t mode) {
+  __posix_spawn_file_action* action =
+      reinterpret_cast<__posix_spawn_file_action*>(malloc(sizeof(*action)));
+  if (action == nullptr) return errno;
+
+  action->next = nullptr;
+  if (path != nullptr) {
+    action->path = strdup(path);
+    if (action->path == nullptr) {
+      free(action);
+      return errno;
+    }
+  } else {
+    action->path = nullptr;
+  }
+  action->what = what;
+  action->fd = fd;
+  action->new_fd = new_fd;
+  action->flags = flags;
+  action->mode = mode;
+
+  if ((*actions)->head == nullptr) {
+    (*actions)->head = (*actions)->last = action;
+  } else {
+    (*actions)->last->next = action;
+    (*actions)->last = action;
+  }
+
+  return 0;
+}
+
+int posix_spawn_file_actions_addopen(posix_spawn_file_actions_t* actions,
+                                     int fd, const char* path, int flags, mode_t mode) {
+  if (fd < 0) return EBADF;
+  return posix_spawn_add_file_action(actions, kOpen, -1, fd, path, flags, mode);
+}
+
+int posix_spawn_file_actions_addclose(posix_spawn_file_actions_t* actions, int fd) {
+  if (fd < 0) return EBADF;
+  return posix_spawn_add_file_action(actions, kClose, fd, -1, nullptr, 0, 0);
+}
+
+int posix_spawn_file_actions_adddup2(posix_spawn_file_actions_t* actions, int fd, int new_fd) {
+  if (fd < 0 || new_fd < 0) return EBADF;
+  return posix_spawn_add_file_action(actions, kDup2, fd, new_fd, nullptr, 0, 0);
+}