diff --git a/libc/bionic/signal.cpp b/libc/bionic/signal.cpp
index 13d1882..9a23416 100644
--- a/libc/bionic/signal.cpp
+++ b/libc/bionic/signal.cpp
@@ -26,7 +26,108 @@
  * SUCH DAMAGE.
  */
 
+#include <errno.h>
+#include <pthread.h>
 #include <signal.h>
+#include <string.h>
+#include <sys/types.h>
+#include <time.h>
+#include <unistd.h>
+
+#include "private/kernel_sigset_t.h"
+
+extern "C" int ___rt_sigqueueinfo(pid_t, int, siginfo_t*);
+extern "C" int __rt_sigtimedwait(const sigset_t*, siginfo_t*, const timespec*, size_t);
+
+int sigaddset(sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  unsigned long* local_set = reinterpret_cast<unsigned long*>(set);
+  if (set == NULL || bit < 0 || bit >= static_cast<int>(8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  local_set[bit / LONG_BIT] |= 1UL << (bit % LONG_BIT);
+  return 0;
+}
+
+// This isn't in our header files, but is exposed on all architectures.
+extern "C" int sigblock(int mask) {
+  union {
+    int mask;
+    sigset_t set;
+  } in, out;
+
+  sigemptyset(&in.set);
+  in.mask = mask;
+
+  if (sigprocmask(SIG_BLOCK, &in.set, &out.set) == -1) return -1;
+  return out.mask;
+}
+
+int sigdelset(sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  unsigned long* local_set = reinterpret_cast<unsigned long*>(set);
+  if (set == NULL || bit < 0 || bit >= static_cast<int>(8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  local_set[bit / LONG_BIT] &= ~(1UL << (bit % LONG_BIT));
+  return 0;
+}
+
+int sigemptyset(sigset_t* set) {
+  if (set == NULL) {
+    errno = EINVAL;
+    return -1;
+  }
+  memset(set, 0, sizeof(sigset_t));
+  return 0;
+}
+
+int sigfillset(sigset_t* set) {
+  if (set == NULL) {
+    errno = EINVAL;
+    return -1;
+  }
+  memset(set, ~0, sizeof(sigset_t));
+  return 0;
+}
+
+int sighold(int sig) {
+  kernel_sigset_t set;
+  set.clear();
+  if (!set.set(sig)) return -1;
+  return __rt_sigprocmask(SIG_BLOCK, &set, nullptr, sizeof(set));
+}
+
+int sigignore(int sig) {
+  struct sigaction sa;
+  memset(&sa, 0, sizeof(sa));
+  if (sigemptyset(&sa.sa_mask) == -1) return -1;
+  sa.sa_handler = SIG_IGN;
+  return sigaction(sig, &sa, nullptr);
+}
+
+int siginterrupt(int sig, int flag) {
+  struct sigaction act;
+  sigaction(sig, nullptr, &act);
+  if (flag) {
+    act.sa_flags &= ~SA_RESTART;
+  } else {
+    act.sa_flags |= SA_RESTART;
+  }
+  return sigaction(sig, &act, nullptr);
+}
+
+int sigismember(const sigset_t* set, int signum) {
+  int bit = signum - 1; // Signal numbers start at 1, but bit positions start at 0.
+  const unsigned long* local_set = reinterpret_cast<const unsigned long*>(set);
+  if (set == NULL || bit < 0 || bit >= static_cast<int>(8*sizeof(sigset_t))) {
+    errno = EINVAL;
+    return -1;
+  }
+  return static_cast<int>((local_set[bit / LONG_BIT] >> (bit % LONG_BIT)) & 1);
+}
 
 __LIBC_HIDDEN__ sighandler_t _signal(int signum, sighandler_t handler, int flags) {
   struct sigaction sa;
@@ -44,3 +145,127 @@
 sighandler_t signal(int signum, sighandler_t handler) {
   return _signal(signum, handler, SA_RESTART);
 }
+
+int sigpause(int sig) {
+  kernel_sigset_t set;
+  set.clear();
+  if (__rt_sigprocmask(SIG_SETMASK, nullptr, &set, sizeof(set)) == -1) return -1;
+  if (!set.clear(sig)) return -1;
+  return __rt_sigsuspend(&set, sizeof(set));
+}
+
+int sigpending(sigset_t* bionic_set) {
+  kernel_sigset_t set;
+  int result = __rt_sigpending(&set, sizeof(set));
+  if (result != -1) {
+    *bionic_set = set.bionic;
+  }
+  return result;
+}
+
+int sigprocmask(int how, const sigset_t* bionic_new_set, sigset_t* bionic_old_set) {
+  kernel_sigset_t new_set;
+  kernel_sigset_t* new_set_ptr = NULL;
+  if (bionic_new_set != NULL) {
+    new_set.set(bionic_new_set);
+    new_set_ptr = &new_set;
+  }
+
+  kernel_sigset_t old_set;
+  if (__rt_sigprocmask(how, new_set_ptr, &old_set, sizeof(old_set)) == -1) {
+    return -1;
+  }
+
+  if (bionic_old_set != NULL) {
+    *bionic_old_set = old_set.bionic;
+  }
+
+  return 0;
+}
+
+int sigqueue(pid_t pid, int signo, const sigval value) {
+  siginfo_t info;
+  memset(&info, 0, sizeof(siginfo_t));
+  info.si_signo = signo;
+  info.si_code = SI_QUEUE;
+  info.si_pid = getpid();
+  info.si_uid = getuid();
+  info.si_value = value;
+
+  return ___rt_sigqueueinfo(pid, signo, &info);
+}
+
+int sigrelse(int sig) {
+  kernel_sigset_t set;
+  set.clear();
+  if (!set.set(sig)) return -1;
+  return __rt_sigprocmask(SIG_UNBLOCK, &set, nullptr, sizeof(set));
+}
+
+sighandler_t sigset(int sig, sighandler_t disp) {
+  struct sigaction new_sa;
+  if (disp != SIG_HOLD) {
+    memset(&new_sa, 0, sizeof(new_sa));
+    new_sa.sa_handler = disp;
+    sigemptyset(&new_sa.sa_mask);
+  }
+
+  struct sigaction old_sa;
+  if (sigaction(sig, (disp == SIG_HOLD) ? nullptr : &new_sa, &old_sa) == -1) {
+    return SIG_ERR;
+  }
+
+  kernel_sigset_t new_mask{sig};
+  kernel_sigset_t old_mask;
+  if (__rt_sigprocmask(disp == SIG_HOLD ? SIG_BLOCK : SIG_UNBLOCK, &new_mask, &old_mask,
+                       sizeof(new_mask)) == -1) {
+    return SIG_ERR;
+  }
+
+  return old_mask.is_set(sig) ? SIG_HOLD : old_sa.sa_handler;
+}
+
+// This isn't in our header files, but is exposed on all architectures.
+extern "C" int sigsetmask(int mask) {
+  union {
+    int mask;
+    sigset_t set;
+  } in, out;
+
+  sigemptyset(&in.set);
+  in.mask = mask;
+
+  if (sigprocmask(SIG_SETMASK, &in.set, &out.set) == -1) return -1;
+  return out.mask;
+}
+
+int sigsuspend(const sigset_t* bionic_set) {
+  kernel_sigset_t set(bionic_set);
+  return __rt_sigsuspend(&set, sizeof(set));
+}
+
+int sigtimedwait(const sigset_t* set, siginfo_t* info, const timespec* timeout) {
+  kernel_sigset_t sigset(set);
+  return __rt_sigtimedwait(sigset.get(), info, timeout, sizeof(sigset));
+}
+
+int sigwait(const sigset_t* set, int* sig) {
+  kernel_sigset_t sigset(set);
+  while (true) {
+    // __rt_sigtimedwait can return EAGAIN or EINTR, we need to loop
+    // around them since sigwait is only allowed to return EINVAL.
+    int result = __rt_sigtimedwait(sigset.get(), NULL, NULL, sizeof(sigset));
+    if (result >= 0) {
+      *sig = result;
+      return 0;
+    }
+
+    if (errno != EAGAIN && errno != EINTR) {
+      return errno;
+    }
+  }
+}
+
+int sigwaitinfo(const sigset_t* set, siginfo_t* info) {
+  return sigtimedwait(set, info, NULL);
+}