ld crash when PHDRS uses undefined names

ld crash when PHDRS uses undefined names

[Roland McGrath]

If a PHDRS statement uses unrecognized names for phdr types, ld crashes.
A test case is easy to concoct.  This patch makes unrecognized names a
graceful error, and also makes it grok the recently added PT_* names.
I put the literal value for PT_GNU_EH_FRAME in there instead of futzing
with header inclusion, since it keeps the change simple and the array there
already implicits hard-codes literal values for the low-valued PT_* names.

The "$$ = exp_intop (0);" sets a bogus value when a bad name was diagnosed.
That prevents it from crashing later on.  I don't know if there is a better
way to do it.

Someone gave me write access at some point, so I can commit with approval
if that is most convenient for whoever does the approving.


Thanks,
Roland


2003-04-23  Roland McGrath  <roland@redhat.com>

	* ldgram.y (phdr_type): Grok PT_TLS and PT_GNU_EH_FRAME names.
	If a name string is unknown, give an error rather than crashing later.

--- binutils/ld/ldgram.y.~1.24.~	Fri Feb 28 12:22:01 2003
+++ binutils/ld/ldgram.y	Wed Apr 23 01:32:20 2003
@@ -990,7 +990,7 @@ phdr_type:
 			{
 			  "PT_NULL", "PT_LOAD", "PT_DYNAMIC",
 			  "PT_INTERP", "PT_NOTE", "PT_SHLIB",
-			  "PT_PHDR"
+			  "PT_PHDR", "PT_TLS"
 			};
 
 		      s = $1->name.name;
@@ -1002,6 +1002,18 @@ phdr_type:
 			    $$ = exp_intop (i);
 			    break;
 			  }
+		      if (i == sizeof phdr_types / sizeof phdr_types[0])
+			{
+			  if (strcmp (s, "PT_GNU_EH_FRAME") == 0)
+			    $$ = exp_intop (0x6474e550);
+			  else
+			    {
+			      einfo (_("\
+%X%P:%S: unknown phdr type `%s' (try integer literal)\n"),
+				     s);
+			      $$ = exp_intop (0);
+			    }
+			}
 		    }
 		}
 	;

Re: ld crash when PHDRS uses undefined names

[Nick Clifton]

Hi Roland,

> 2003-04-23  Roland McGrath  <roland@redhat.com>
> 
> 	* ldgram.y (phdr_type): Grok PT_TLS and PT_GNU_EH_FRAME names.
> 	If a name string is unknown, give an error rather than crashing later.

Approved - please apply.

Note - it would be cleaner if the phdr_types[] table had a direct
mapping between the name and its integer value, so that you did not 
have to have the special case code for the PT_GNU_EH_FRAME.  Still
this is not a high priority change.

Cheers
        Nick

Re: ld crash when PHDRS uses undefined names

[Roland McGrath]

> Approved - please apply.

Done.

> Note - it would be cleaner if the phdr_types[] table had a direct
> mapping between the name and its integer value, so that you did not 
> have to have the special case code for the PT_GNU_EH_FRAME.  Still
> this is not a high priority change.

I agree.  But I was fixing a crash, not trying to improve the source,
so I just made the minimal necessary change.