Add posix_spawn (#114)

libc/calls/getuid.c

@@ -41,40 +41,36 @@ static textwindows noinline uint32_t GetUserNameHash(void) {
   return KnuthMultiplicativeHash32(buf, size >> 1);
 }
 
-static uint32_t getuidgid(int at, uint32_t impl(void)) {
+/**
+ * Returns real user id of process.
+ *
+ * This never fails. On Windows, which doesn't really have this concept,
+ * we return a deterministic value that's likely to work.
+ *
+ * @asyncsignalsafe
+ * @vforksafe
+ */
+uint32_t getuid(void) {
   if (!IsWindows()) {
-    if (at != -1) {
-      return getauxval(at);
-    } else {
-      return impl();
-    }
+    return sys_getuid();
   } else {
     return GetUserNameHash();
   }
 }
 
-/**
- * Returns real user id of process.
- *
- * This never fails. On Windows, which doesn't really have this concept,
- * we return a deterministic value that's likely to work. On Linux, this
- * is fast.
- *
- * @asyncsignalsafe
- */
-uint32_t getuid(void) {
-  return getuidgid(AT_UID, sys_getuid);
-}
-
 /**
  * Returns real group id of process.
  *
  * This never fails. On Windows, which doesn't really have this concept,
- * we return a deterministic value that's likely to work. On Linux, this
- * is fast.
+ * we return a deterministic value that's likely to work.
  *
  * @asyncsignalsafe
+ * @vforksafe
  */
 uint32_t getgid(void) {
-  return getuidgid(AT_GID, sys_getgid);
+  if (!IsWindows()) {
+    return sys_getgid();
+  } else {
+    return GetUserNameHash();
+  }
 }

libc/calls/sigfillset.c

@@ -24,6 +24,7 @@
  *
  * @return 0 on success, or -1 w/ errno
  * @asyncsignalsafe
+ * @vforksafe
  */
 int sigfillset(sigset_t *set) {
   memset(set->__bits, -1, sizeof(set->__bits));

libc/calls/sigismember.c

@@ -24,6 +24,7 @@
  *
  * @return true, false, or -1 w/ errno
  * @asyncsignalsafe
+ * @vforksafe
  */
 int sigismember(const sigset_t *set, int sig) {
   unsigned i = sig - 1;