Fix failures in MMIX linker tests introduced by fix for PR 21665.

	PR binutils/21665
	* objdump.c (disassemble_section): Move check for an overlarge
	section to just before the allocation of memory.  Do not check
	section size against file size, but instead use an arbitrary 2Gb
	limit.  Issue a warning message if the section is too big.

diff --git a/binutils/ChangeLog b/binutils/ChangeLog
index 0496c99..ff41d22 100644 (file)
--- a/binutils/ChangeLog
+++ b/binutils/ChangeLog
@@ -1,3 +1,11 @@
+2017-06-30  Nick Clifton  <nickc@redhat.com>
+
+       PR binutils/21665
+       * objdump.c (disassemble_section): Move check for an overlarge
+       section to just before the allocation of memory.  Do not check
+       section size against file size, but instead use an arbitrary 2Gb
+       limit.  Issue a warning message if the section is too big.
+
 2017-06-30  Maciej W. Rozycki  <macro@imgtec.com>
 
        * NEWS: Mention microMIPS XPA support.

diff --git a/binutils/objdump.c b/binutils/objdump.c
index 0b72818..d70882e 100644 (file)
--- a/binutils/objdump.c
+++ b/binutils/objdump.c
@@ -2114,7 +2114,7 @@ disassemble_section (bfd *abfd, asection *section, void *inf)
     return;
 
   datasize = bfd_get_section_size (section);
-  if (datasize == 0 || datasize >= (bfd_size_type) bfd_get_file_size (abfd))
+  if (datasize == 0)
     return;
 
   if (start_address == (bfd_vma) -1
@@ -2178,6 +2178,29 @@ disassemble_section (bfd *abfd, asection *section, void *inf)
     }
   rel_ppend = rel_pp + rel_count;
 
+  /* PR 21665: Check for overlarge datasizes.
+     Note - we used to check for "datasize > bfd_get_file_size (abfd)" but
+     this fails when using compressed sections or compressed file formats
+     (eg MMO, tekhex).
+
+     The call to xmalloc below will fail if too much memory is requested,
+     which will catch the problem in the normal use case.  But if a memory
+     checker is in use, eg valgrind or sanitize, then an exception will
+     be still generated, so we try to catch the problem first.
+
+     Unfortunately there is no simple way to determine how much memory can
+     be allocated by calling xmalloc.  So instead we use a simple, arbitrary
+     limit of 2Gb.  Hopefully this should be enough for most users.  If
+     someone does start trying to disassemble sections larger then 2Gb in
+     size they will doubtless complain and we can increase the limit.  */
+#define MAX_XMALLOC (1024 * 1024 * 1024 * 2UL) /* 2Gb */
+  if (datasize > MAX_XMALLOC)
+    {
+      non_fatal (_("Reading section %s failed because it is too big (%#lx)"),
+                section->name, (unsigned long) datasize);
+      return;
+    }
+
   data = (bfd_byte *) xmalloc (datasize);
 
   if (!bfd_get_section_contents (abfd, section, data, 0, datasize))