PR 6691 fixed by adding support for sys_accept4.

* tapset/aux_syscalls.stp(_sock_type_str): Rewrote in embedded-C and added
  socket flags support.
  (_sock_flags_str): New function.
* tapset/syscalls.stp: syscall.accept prefers to use sys_accept4 when it
  exists.  Added support for sys_accept4's 'flag' parameter.
* testsuite/systemtap.syscall/net1.c (main): Updated regular expression to
  handle the new 'flags' argument.

3 files changed, 88 insertions, 16 deletions

diff --git a/tapset/aux_syscalls.stp b/tapset/aux_syscalls.stp
index 9347e46f..2f19ab16 100644
--- a/tapset/aux_syscalls.stp
+++ b/tapset/aux_syscalls.stp
@@ -1302,16 +1302,76 @@ function _sock_family_str(f) {
    return sprintf("UNKNOWN VALUE: %d", f)
 }
 
-function _sock_type_str(t) {
-   if(t==1) return "SOCK_STREAM"
-   if(t==2) return "SOCK_DGRAM"
-   if(t==5) return "SOCK_SEQPACKET"
-   if(t==3) return "SOCK_RAW"
-   if(t==4) return "SOCK_RDM"
-   if(t==6) return "SOCK_DCCP"
-   if(t==10) return "SOCK_PACKET"
-   return sprintf("UNKNOWN VALUE: %d", t)
-}
+function _sock_type_str:string(type:long)
+%{ /* pure */
+#ifdef SOCK_TYPE_MASK
+	int flags = (int)THIS->type & ~SOCK_TYPE_MASK;
+	int t = (int)THIS->type & SOCK_TYPE_MASK;
+#else
+	int t = (int)THIS->type;
+#endif
+
+	switch (t) {
+	case SOCK_STREAM:
+		strlcpy (THIS->__retvalue, "SOCK_STREAM", MAXSTRINGLEN);
+		break;
+	case SOCK_DGRAM:
+		strlcpy (THIS->__retvalue, "SOCK_DGRAM", MAXSTRINGLEN);
+		break;
+	case SOCK_RAW:
+		strlcpy (THIS->__retvalue, "SOCK_RAW", MAXSTRINGLEN);
+		break;
+	case SOCK_RDM:
+		strlcpy (THIS->__retvalue, "SOCK_RDM", MAXSTRINGLEN);
+		break;
+	case SOCK_SEQPACKET:
+		strlcpy (THIS->__retvalue, "SOCK_SEQPACKET", MAXSTRINGLEN);
+		break;
+#ifdef SOL_DCCP
+	case SOCK_DCCP:
+		strlcpy (THIS->__retvalue, "SOCK_DCCP", MAXSTRINGLEN);
+		break;
+#endif
+	case SOCK_PACKET:
+		strlcpy (THIS->__retvalue, "SOCK_PACKET", MAXSTRINGLEN);
+		break;
+	default:
+		strlcpy (THIS->__retvalue, "UNKNOWN VALUE: %d", t);
+		break;
+	}
+
+#ifdef SOCK_TYPE_MASK
+	if (flags & SOCK_CLOEXEC) {
+		strlcat (THIS->__retvalue, "|SOCK_CLOEXEC", MAXSTRINGLEN);
+	}
+	if (flags & SOCK_NONBLOCK) {
+		strlcat (THIS->__retvalue, "|SOCK_NONBLOCK", MAXSTRINGLEN);
+	}
+#endif
+%}
+
+function _sock_flags_str:string(f:long)
+%{ /* pure */
+#ifdef SOCK_TYPE_MASK
+	int flags = (int)THIS->f;
+	int len;
+
+	THIS->__retvalue[0] = '\0';
+	if (flags & SOCK_CLOEXEC) {
+		strlcat (THIS->__retvalue, "SOCK_CLOEXEC|", MAXSTRINGLEN);
+	}
+	if (flags & SOCK_NONBLOCK) {
+		strlcat (THIS->__retvalue, "SOCK_NONBLOCK|", MAXSTRINGLEN);
+	}
+	len = strlen(THIS->__retvalue);
+	if (len) {
+		THIS->__retvalue[len - 1] = '\0';
+	}
+	else {
+		strlcat (THIS->__retvalue, "0", MAXSTRINGLEN);
+	}
+#endif
+%}
 
 function _opoll_op_str(o) {
    if(o==1) return "EPOLL_CTL_ADD"
diff --git a/tapset/syscalls.stp b/tapset/syscalls.stp
index 825842a6..dde0ca9f 100644
--- a/tapset/syscalls.stp
+++ b/tapset/syscalls.stp
@@ -27,17 +27,29 @@
 
 # accept _____________________________________________________
 # long sys_accept(int fd, struct sockaddr __user *upeer_sockaddr,
-#                 int __user *upeer_addrlen)
-probe syscall.accept = kernel.function("SyS_accept").call !,
-                       kernel.function("sys_accept").call ?
+#                 int __user *upeer_addrlen, int flags)
+probe syscall.accept = _syscall.accept4 !, _syscall.accept
 {
 	name = "accept"
 	sockfd = $fd
 	addr_uaddr = $upeer_sockaddr
 	addrlen_uaddr = $upeer_addrlen
-	argstr = sprintf("%d, %p, %p", $fd, $upeer_sockaddr, $upeer_addrlen)
+	argstr = sprintf("%d, %p, %p, %s", $fd, $upeer_sockaddr,
+		$upeer_addrlen, flags_str)
 }
-probe syscall.accept.return = kernel.function("SyS_accept").return !,
+probe _syscall.accept4 = kernel.function("sys_accept4").call
+{
+	flags = $flags
+	flags_str = _sock_flags_str($flags)
+}
+probe _syscall.accept = kernel.function("SyS_accept").call !,
+                        kernel.function("sys_accept").call ?
+{
+	flags = 0
+	flags_str = "0"
+}
+probe syscall.accept.return = kernel.function("sys_accept4").return !,
+                              kernel.function("SyS_accept").return !,
                               kernel.function("sys_accept").return ?
 {
 	name = "accept"
diff --git a/testsuite/systemtap.syscall/net1.c b/testsuite/systemtap.syscall/net1.c
index f8079ffd..b7f1d6cb 100644
--- a/testsuite/systemtap.syscall/net1.c
+++ b/testsuite/systemtap.syscall/net1.c
@@ -32,7 +32,7 @@ int main()
   //staptest// listen (NNNN, 7) = 0
 
   cfd = accept(listenfd, (struct sockaddr *)NULL, NULL);
-  //staptest// accept (NNNN, 0x[0]+, 0x[0]+) = -NNNN (EAGAIN)
+  //staptest// accept (NNNN, 0x[0]+, 0x[0]+, 0) = -NNNN (EAGAIN)
 
   close(cfd);
   close(listenfd);