Fix memory leak in MacOS process handling.

runtime/bin/process_linux.cc

 // Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include "bin/process.h"
 
 #include <errno.h>
 #include <fcntl.h>
 #include <signal.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include "bin/fdutils.h"
 
+
 class ProcessInfo {
  public:
   ProcessInfo(pid_t pid, intptr_t fd) : pid_(pid), fd_(fd) { }
 
   pid_t pid() { return pid_; }
   intptr_t fd() { return fd_; }
   ProcessInfo* next() { return next_; }
   void set_next(ProcessInfo* next) { next_ = next; }
 
  private:
@@ skipping 80 matching lines @@
           FDUtils::WriteToBlocking(process->fd(), &message, sizeof(message));
       if (result != sizeof(message) && errno != EPIPE) {
         perror("ExitHandler notification failed");
       }
       close(process->fd());
     }
   }
 }
 
 
+static void ReportChildError(int exec_control_fd) {
+  // In the case of failure in the child process write the errno and
+  // the OS error message to the exec control pipe and exit.
+  int child_errno = errno;
+  char* os_error_message = strerror(errno);
+  ASSERT(sizeof(child_errno) == sizeof(errno));
+  int bytes_written =
+      FDUtils::WriteToBlocking(
+          exec_control_fd, &child_errno, sizeof(child_errno));
+  if (bytes_written == sizeof(child_errno)) {
+    FDUtils::WriteToBlocking(
+        exec_control_fd, os_error_message, strlen(os_error_message) + 1);
+  }
+  close(exec_control_fd);
+  exit(1);
+}
+
+
 int Process::Start(const char* path,
                    char* arguments[],
                    intptr_t arguments_length,
                    intptr_t* in,
                    intptr_t* out,
                    intptr_t* err,
                    intptr_t* id,
                    intptr_t* exit_event,
                    char* os_error_message,
                    int os_error_message_len) {
@@ skipping 95 matching lines @@
     if (bytes_read != sizeof(msg)) {
       perror("Failed receiving notification message");
       exit(1);
     }
 
     close(write_out[1]);
     close(read_in[0]);
     close(read_err[0]);
     close(exec_control[0]);
 
-    dup2(write_out[0], STDIN_FILENO);
+    if (dup2(write_out[0], STDIN_FILENO) == -1) {
+      ReportChildError(exec_control[1]);
+    }
     close(write_out[0]);
 
-    dup2(read_in[1], STDOUT_FILENO);
+    if (dup2(read_in[1], STDOUT_FILENO) == -1) {
+      ReportChildError(exec_control[1]);
+    }
     close(read_in[1]);
 
-    dup2(read_err[1], STDERR_FILENO);
+    if (dup2(read_err[1], STDERR_FILENO) == -1) {
+      ReportChildError(exec_control[1]);
+    }
     close(read_err[1]);
 
     execvp(path, const_cast<char* const*>(program_arguments));
-    // In the case of failure write the errno and the OS error message
-    // to the exec control pipe.
-    int child_errno = errno;
-    char* os_error_message = strerror(errno);
-    ASSERT(sizeof(child_errno) == sizeof(errno));
-    int bytes_written =
-        FDUtils::WriteToBlocking(
-            exec_control[1], &child_errno, sizeof(child_errno));
-    if (bytes_written == sizeof(child_errno)) {
-      FDUtils::WriteToBlocking(
-          exec_control[1], os_error_message, strlen(os_error_message) + 1);
-    }
-    close(exec_control[1]);
-    exit(1);
+    ReportChildError(exec_control[1]);
   }
 
   // The arguments for the spawned process are not needed any longer.
   delete[] program_arguments;
 
   int event_fds[2];
   result = pipe(event_fds);
   if (result < 0) {
     SetChildOsErrorMessage(os_error_message, os_error_message_len);
     close(read_in[0]);
@@ skipping 71 matching lines @@
   if (result == -1) {
     return false;
   }
   return true;
 }
 
 
 void Process::Exit(intptr_t id) {
   RemoveProcess(id);
 }