From 03a698b9c68622789eb78228409d8a82d22ddd3f Mon Sep 17 00:00:00 2001
From: Ben Noordhuis <info@bnoordhuis.nl>
Date: Wed, 27 Apr 2022 22:44:00 +0200
Subject: [PATCH] unix: use MSG_CMSG_CLOEXEC where supported (#3609)

Use MSG_CMSG_CLOEXEC on Unix-y platforms that support it (all except
macOS and SunOS spawn.)

Remove the feature test for Linux. Libuv's kernel baseline is 2.6.32
and MSG_CMSG_CLOEXEC was added in 2.6.23.
---
 src/unix/core.c | 32 ++++++++++++++------------------
 1 file changed, 14 insertions(+), 18 deletions(-)

diff --git a/src/unix/core.c b/src/unix/core.c
index d5758de4..ca369989 100644
--- a/src/unix/core.c
+++ b/src/unix/core.c
@@ -667,28 +667,23 @@ int uv__cloexec(int fd, int set) {
 
 
 ssize_t uv__recvmsg(int fd, struct msghdr* msg, int flags) {
-  struct cmsghdr* cmsg;
+#if defined(__ANDROID__)   || \
+    defined(__DragonFly__) || \
+    defined(__FreeBSD__)   || \
+    defined(__NetBSD__)    || \
+    defined(__OpenBSD__)   || \
+    defined(__linux__)
   ssize_t rc;
+  rc = recvmsg(fd, msg, flags | MSG_CMSG_CLOEXEC);
+  if (rc == -1)
+    return UV__ERR(errno);
+  return rc;
+#else
+  struct cmsghdr* cmsg;
   int* pfd;
   int* end;
-#if defined(__linux__)
-  static int no_msg_cmsg_cloexec;
-  if (0 == uv__load_relaxed(&no_msg_cmsg_cloexec)) {
-    rc = recvmsg(fd, msg, flags | 0x40000000);  /* MSG_CMSG_CLOEXEC */
-    if (rc != -1)
-      return rc;
-    if (errno != EINVAL)
-      return UV__ERR(errno);
-    rc = recvmsg(fd, msg, flags);
-    if (rc == -1)
-      return UV__ERR(errno);
-    uv__store_relaxed(&no_msg_cmsg_cloexec, 1);
-  } else {
-    rc = recvmsg(fd, msg, flags);
-  }
-#else
+  ssize_t rc;
   rc = recvmsg(fd, msg, flags);
-#endif
   if (rc == -1)
     return UV__ERR(errno);
   if (msg->msg_controllen == 0)
@@ -701,6 +696,7 @@ ssize_t uv__recvmsg(int fd, struct msghdr* msg, int flags) {
            pfd += 1)
         uv__cloexec(*pfd, 1);
   return rc;
+#endif
 }