[NaCl SDK] nacl_io: Fix utime() on directories.

native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc

Index: native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
diff --git a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
index 89c8e36db7c341a23eb96d91b6443092d7851d67..db6f42baa2a9a82961bba9116b94bb52cfeaa7fe 100644
--- a/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
+++ b/native_client_sdk/src/libraries/nacl_io/kernel_proxy.cc
@@ -209,7 +209,7 @@ int KernelProxy::open_resource(const char* path) {
 int KernelProxy::open(const char* path, int open_flags, mode_t mode) {
   ScopedFilesystem fs;
   ScopedNode node;
-  mode_t mask = ~GetUmask();
+  mode_t mask = ~GetUmask() & 0777;
 
   Error error = AcquireFsAndNode(path, open_flags, mode & mask, &fs, &node);
   if (error) {
@@ -372,7 +372,8 @@ int KernelProxy::mkdir(const char* path, mode_t mode) {
     return -1;
   }
 
-  error = fs->Mkdir(rel, mode & ~GetUmask());
+  mode_t mask = ~GetUmask() & 0777;
+  error = fs->Mkdir(rel, mode & mask);
   if (error) {
     errno = error;
     return -1;
@@ -792,6 +793,11 @@ int KernelProxy::truncate(const char* path, off_t len) {
     return -1;
   }
 
+  // Directories cannot be truncated.
+  if (node->IsaDir()) {
+    return EISDIR;
+  }
+
   if (!node->CanOpen(O_WRONLY)) {
     errno = EACCES;
     return -1;
@@ -873,7 +879,7 @@ int KernelProxy::fchmod(int fd, mode_t mode) {
     return -1;
   }
 
-  error = handle->node()->Fchmod(mode);
+  error = handle->node()->Fchmod(mode & 0777);
   if (error) {
     errno = error;
     return -1;
@@ -1184,7 +1190,7 @@ int KernelProxy::sigaction(int signum,
 }
 
 mode_t KernelProxy::umask(mode_t mask) {
-  return SetUmask(mask);
+  return SetUmask(mask & 0777);
 }
 
 #ifdef PROVIDES_SOCKET_API