RISC-V/GAS: Improve handling of invalid relocs

TLS relocs against constants previously segfaulted, and illegal symbol subtractions were silently ignored. The previous behavior was to segfault. gas/ChangeLog 2016-12-21 Andrew Waterman <[email protected]> * config/tc-riscv.c (md_apply_fix): Report TLS relocations against constants. Report disallowed symbol subtractions.
riscvarchive · Jan 9, 2017 · f1d775f · f1d775f
1 parent 8dcba69
commit f1d775f
Showing 1 changed file with 9 additions and 1 deletion.
diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
@@ -1889,7 +1889,11 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
     case BFD_RELOC_RISCV_TLS_GD_HI20:
     case BFD_RELOC_RISCV_TLS_DTPREL32:
     case BFD_RELOC_RISCV_TLS_DTPREL64:
-      S_SET_THREAD_LOCAL (fixP->fx_addsy);
+      if (fixP->fx_addsy != NULL)
+	S_SET_THREAD_LOCAL (fixP->fx_addsy);
+      else
+	as_bad_where (fixP->fx_file, fixP->fx_line,
+		      _("TLS relocation against a constant"));
       break;
 
     case BFD_RELOC_64:
@@ -2045,6 +2049,10 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg ATTRIBUTE_UNUSED)
 	as_fatal (_("internal error: bad relocation #%d"), fixP->fx_r_type);
     }
 
+  if (fixP->fx_subsy != NULL)
+    as_bad_where (fixP->fx_file, fixP->fx_line,
+		  _("unsupported symbol subtraction"));
+
   /* Add an R_RISCV_RELAX reloc if the reloc is relaxable.  */
   if (relaxable && fixP->fx_tcbit && fixP->fx_addsy != NULL)
     {