From: Andrew Waterman <andrew@sifive.com>
Date: Wed, 21 Dec 2016 20:47:13 +0000 (-0800)
Subject: RISC-V/GAS: Improve handling of invalid relocs
X-Git-Tag: users/ARM/embedded-binutils-2_28-branch-2017q1~60
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2398b2bad9812c7bada17563805ee61f72c8cc87;p=thirdparty%2Fbinutils-gdb.git

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

2017-01-09  Andrew Waterman <andrew@sifive.com>

	* config/tc-riscv.c (md_apply_fix): Report TLS relocations against
	constants.  Report disallowed symbol subtractions.
---

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 266f22e6f33..80857d7e378 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -11,6 +11,12 @@
 	* testsuite/gas/i386/x86-64-avx512_vpopcntdqd.d: Ditto.
 	* testsuite/gas/i386/x86-64-avx512_vpopcntdqd.s: Ditto.
 
+2017-01-09  Andrew Waterman <andrew@sifive.com>
+
+	* config/tc-riscv.c (append_insn): Don't eagerly apply relocations
+	against constants.
+	(md_apply_fix): Mark relocations against constants as "done."
+
 2017-01-09  Palmer Dabbelt <palmer@dabbelt.com>
 	    Kito Cheng <kito.cheng@gmail.com>
 
diff --git a/gas/config/tc-riscv.c b/gas/config/tc-riscv.c
index 3fe9e63a392..bf870e66d85 100644
--- a/gas/config/tc-riscv.c
+++ b/gas/config/tc-riscv.c
@@ -1879,7 +1879,11 @@ 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:
@@ -2035,6 +2039,10 @@ 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)
     {