Don't check the flags word in msghdr for sendmsg as the

kernel will neither read nor write it.

Patch from Mark Wielaard to fix BZ#315441.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13294

coregrind/m_syswrap/syswrap-generic.c

@@ -849,7 +849,8 @@ void msghdr_foreachfield (
         const HChar *name,
         struct vki_msghdr *msg,
         UInt length,
-        void (*foreach_func)( ThreadId, Bool, const HChar *, Addr, SizeT ) 
+        void (*foreach_func)( ThreadId, Bool, const HChar *, Addr, SizeT ),
+        Bool recv
      )
 {
    HChar *fieldName;
@@ -867,7 +868,11 @@ void msghdr_foreachfield (
    foreach_func ( tid, True, fieldName, (Addr)&msg->msg_iovlen, sizeof( msg->msg_iovlen ) );
    foreach_func ( tid, True, fieldName, (Addr)&msg->msg_control, sizeof( msg->msg_control ) );
    foreach_func ( tid, True, fieldName, (Addr)&msg->msg_controllen, sizeof( msg->msg_controllen ) );
-   foreach_func ( tid, False, fieldName, (Addr)&msg->msg_flags, sizeof( msg->msg_flags ) );
+
+   /* msg_flags is completely ignored for send_mesg, recv_mesg doesn't read
+      the field, but does write to it. */
+   if ( recv )
+      foreach_func ( tid, False, fieldName, (Addr)&msg->msg_flags, sizeof( msg->msg_flags ) );
 
    if ( msg->msg_name ) {
       VG_(sprintf) ( fieldName, "(%s.msg_name)", name );
@@ -1512,7 +1517,7 @@ void
 ML_(generic_PRE_sys_sendmsg) ( ThreadId tid, const HChar *name,
                                struct vki_msghdr *msg )
 {
-   msghdr_foreachfield ( tid, name, msg, ~0, pre_mem_read_sendmsg );
+   msghdr_foreachfield ( tid, name, msg, ~0, pre_mem_read_sendmsg, False );
 }
 
 /* ------ */
@@ -1521,14 +1526,14 @@ void
 ML_(generic_PRE_sys_recvmsg) ( ThreadId tid, const HChar *name,
                                struct vki_msghdr *msg )
 {
-   msghdr_foreachfield ( tid, name, msg, ~0, pre_mem_write_recvmsg );
+   msghdr_foreachfield ( tid, name, msg, ~0, pre_mem_write_recvmsg, True );
 }
 
 void 
 ML_(generic_POST_sys_recvmsg) ( ThreadId tid, const HChar *name,
                                 struct vki_msghdr *msg, UInt length )
 {
-   msghdr_foreachfield( tid, name, msg, length, post_mem_write_recvmsg );
+   msghdr_foreachfield( tid, name, msg, length, post_mem_write_recvmsg, True );
    check_cmsg_for_fds( tid, msg );
 }
 

memcheck/tests/Makefile.am

@@ -187,6 +187,7 @@ EXTRA_DIST = \
 	recursive-merge.stderr.exp recursive-merge.vgtest \
 	sbfragment.stdout.exp sbfragment.stderr.exp sbfragment.vgtest \
 	sem.stderr.exp sem.vgtest \
+	sendmsg.stderr.exp sendmsg.vgtest \
 	sh-mem.stderr.exp sh-mem.vgtest \
 	sh-mem-random.stderr.exp sh-mem-random.stdout.exp64 \
 	sh-mem-random.stdout.exp sh-mem-random.vgtest \
@@ -292,6 +293,7 @@ check_PROGRAMS = \
 	realloc1 realloc2 realloc3 \
 	recursive-merge \
 	sbfragment \
+	sendmsg \
 	sh-mem sh-mem-random \
 	sigaltstack signal2 sigprocmask static_malloc sigkill \
 	strchr \

memcheck/tests/filter_stderr

@@ -22,6 +22,9 @@ sed "s/checked [0-9,]* bytes./checked ... bytes./" |
 # records.  So we filter out the loss record numbers.
 perl -p -e "s/in loss record \d+ of \d+/in loss record ... of .../" |
 
+# Filter out glibc debuginfo if installed.
+perl -p -e "s/\(syscall-template.S:[0-9]*\)/(in \/...libc...)/" |
+
 $dir/../../memcheck/tests/filter_memcheck "$@"
 
 exit 0

memcheck/tests/sendmsg.c

@@ -0,0 +1,74 @@
+#include <netinet/ip.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#define PORT 12345
+
+int
+main (int argc, char **argv)
+{
+  int fd;
+  struct sockaddr_in sa;
+  struct msghdr msg;
+  struct iovec iov[2];
+
+  fd = socket (AF_INET, SOCK_DGRAM, 0);
+  if (fd == -1)
+    {
+      perror ("socket()");
+      exit (EXIT_FAILURE);
+    }
+
+  sa.sin_family = AF_INET;
+  sa.sin_addr.s_addr = htonl (INADDR_LOOPBACK);
+  sa.sin_port = htons (PORT);
+  if (connect (fd, (struct sockaddr *) &sa, sizeof (sa)) == -1)
+    {
+      perror ("connect ()");
+      exit (EXIT_FAILURE);
+    }
+
+  // Create msg_hdr. Oops, we forget to set msg_name...
+  msg.msg_namelen = 0;
+  iov[0].iov_base = "one";
+  iov[0].iov_len = 3;
+  iov[1].iov_base = "two";
+  iov[1].iov_len = 3;
+  msg.msg_iov = &iov;
+  msg.msg_iovlen = 2;
+  msg.msg_control = NULL;
+  msg.msg_controllen = 0;
+
+  size_t s = sendmsg (fd, &msg, 0);
+
+  // Note how we now do set msg_name, but don't set msg_flags.
+  // The msg_flags field is ignored by sendmsg.
+  msg.msg_name = NULL;
+
+  fd = socket (AF_INET, SOCK_DGRAM, 0);
+  if (fd == -1)
+    {
+      perror ("socket()");
+      exit (EXIT_FAILURE);
+    }
+
+  if (connect (fd, (struct sockaddr *) &sa, sizeof (sa)) == -1)
+    {
+      perror ("connect ()");
+      exit (EXIT_FAILURE);
+    }
+
+  s = sendmsg (fd, &msg, 0);
+  if (s == -1)
+    {
+      perror ("sendmsg ()");
+      exit (EXIT_FAILURE);
+    }
+  else
+    fprintf (stderr, "sendmsg: %d\n", (int) s);
+
+  exit(0);
+}

memcheck/tests/sendmsg.stderr.exp

@@ -0,0 +1,6 @@
+Syscall param sendmsg(msg) points to uninitialised byte(s)
+   at 0x........: sendmsg (in /...libc...)
+   by 0x........: main (sendmsg.c:45)
+ Address 0x........ is on thread 1's stack
+
+sendmsg: 6

memcheck/tests/sendmsg.vgtest

@@ -0,0 +1,2 @@
+prog: sendmsg
+vgopts: -q