From: Alan Modra <amodra@gmail.com>
Date: Tue, 10 Mar 2020 02:52:25 +0000 (+1030)
Subject: objdump disassembly of files without symbols
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=41da082238bbc3bbe8bac1b0fbcab716fe7c87f2;p=binutils-gdb.git

objdump disassembly of files without symbols

ubsan complains about memcpy with a NULL src even when size is zero.

	* objdump.c (disassemble_section): Don't call qsort unless
	sym count is at least two.
	(disassemble_data): Don't call memcpy with NULL src.
---

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 05c29397f83..fc456a2259d 100644
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,9 @@
+2020-03-10  Alan Modra  <amodra@gmail.com>
+
+	* objdump.c (disassemble_section): Don't call qsort unless
+	sym count is at least two.
+	(disassemble_data): Don't call memcpy with NULL src.
+
 2020-03-09  Alan Modra  <amodra@gmail.com>
 
 	PR 25645
diff --git a/binutils/objdump.c b/binutils/objdump.c
index 6eef38f0e28..211be9239f8 100644
--- a/binutils/objdump.c
+++ b/binutils/objdump.c
@@ -3109,7 +3109,8 @@ disassemble_section (bfd *abfd, asection *section, void *inf)
 
   /* Sort the symbols into value and section order.  */
   compare_section = section;
-  qsort (sorted_syms, sorted_symcount, sizeof (asymbol *), compare_symbols);
+  if (sorted_symcount > 1)
+    qsort (sorted_syms, sorted_symcount, sizeof (asymbol *), compare_symbols);
 
   /* Skip over the relocs belonging to addresses below the
      start address.  */
@@ -3376,10 +3377,13 @@ disassemble_data (bfd *abfd)
   sorted_symcount = symcount ? symcount : dynsymcount;
   sorted_syms = (asymbol **) xmalloc ((sorted_symcount + synthcount)
                                       * sizeof (asymbol *));
-  memcpy (sorted_syms, symcount ? syms : dynsyms,
-	  sorted_symcount * sizeof (asymbol *));
+  if (sorted_symcount != 0)
+    {
+      memcpy (sorted_syms, symcount ? syms : dynsyms,
+	      sorted_symcount * sizeof (asymbol *));
 
-  sorted_symcount = remove_useless_symbols (sorted_syms, sorted_symcount);
+      sorted_symcount = remove_useless_symbols (sorted_syms, sorted_symcount);
+    }
 
   for (i = 0; i < synthcount; ++i)
     {