Fix descriptor leak in multi-target debugging

Summary:
When debugging two targets concurrently, the pseude terminal master fd from the first one would
leak into the second. This fixes the problem by setting O_CLOEXEC on the master fd. Test
included.

Reviewers: clayborg, vharron

Subscribers: lldb-commits

Differential Revision: http://reviews.llvm.org/D7466

llvm-svn: 228570

1 files changed, 3 insertions, 2 deletions

diff --git a/lldb/source/Utility/PseudoTerminal.cpp b/lldb/source/Utility/PseudoTerminal.cpp
index e90955d37d4..55d4a9a1fc1 100644
--- a/lldb/source/Utility/PseudoTerminal.cpp
+++ b/lldb/source/Utility/PseudoTerminal.cpp
@@ -239,7 +239,7 @@ PseudoTerminal::Fork (char *error_str, size_t error_len)
         error_str[0] = '\0';
 
     pid_t pid = LLDB_INVALID_PROCESS_ID;
-    if (OpenFirstAvailableMaster (O_RDWR, error_str, error_len))
+    if (OpenFirstAvailableMaster (O_RDWR | O_CLOEXEC, error_str, error_len))
     {
         // Successfully opened our master pseudo terminal
 
@@ -258,7 +258,8 @@ PseudoTerminal::Fork (char *error_str, size_t error_len)
             if (OpenSlave (O_RDWR, error_str, error_len))
             {
                 // Successfully opened slave
-                // We are done with the master in the child process so lets close it
+
+                // Master FD should have O_CLOEXEC set, but let's close it just in case...
                 CloseMasterFileDescriptor ();
 
 #if defined(TIOCSCTTY)