From 3d61761717d87314f3fbbf751ec81574443af7ec Mon Sep 17 00:00:00 2001
From: Adrian Ratiu <adrian.ratiu@collabora.com>
Date: Tue, 12 Jan 2021 00:46:33 +0200
Subject: [PATCH 13/14] gold: dwp: fix null dereference on executable with no
 refs

A logic error on input validation causes an empty "files" list to
be accepted when DWP is called with only an executable without dwo
references, further causing the "dwo_files" vector creation loop
to no-op then output_file.finalize() to segfault because this->fd_
is NULL.

Fix the input validation and also add an assertion in finalize().
---
 gold/dwp.cc | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/gold/dwp.cc b/gold/dwp.cc
index 7acb9b401bc..cc3eb324f2b 100644
--- a/gold/dwp.cc
+++ b/gold/dwp.cc
@@ -2025,6 +2025,8 @@ Dwp_output_file::finalize()
 {
   unsigned char* buf;
 
+  gold_assert(this->fd_ != NULL);
+
   // Write the accumulated output sections.
   for (unsigned int i = 0; i < this->sections_.size(); i++)
     {
@@ -2670,8 +2672,12 @@ main(int argc, char** argv)
   for (int i = optind; i < argc; ++i)
     files.push_back(Dwo_file_entry(0, argv[i]));
 
-  if (exe_filename == NULL && files.empty())
-    gold_fatal(_("no input files and no executable specified"));
+  if (files.empty())
+    if (exe_filename == NULL)
+	    gold_fatal(_("no input files were specified"));
+    else
+	    gold_fatal(_("specified exe '%s' has no .dwo refs"),
+			 exe_filename);
 
   if (verify_only)
     {
-- 
2.31.1