gas: mips: fix segfault with invalid default cpu strings

If you configure gas for a mips32el-* target, the default cpu calculation
gets mangled, and we end up passing and invalid value as the default cpu.

If you try executing gas after that, it segfaults.  This is because it
assumes that the default cpu value is always valid.
$ ./gas/as-new
Assembler messages:
Error: Bad value (2) for default CPU
Segmentation fault (core dumped)

I'm not debating that the target tuple is valid, just that gas shouldn't
crash.  So add a friendly assert to avoid that.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 116ba37..caef2ba 100644 (file)
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,8 @@
+2012-05-21  Mike Frysinger  <vapier@gentoo.org>
+
+       * config/tc-mips.c (mips_after_parse_args): Assert that arch_info
+       is non-NULL.
+
 2012-05-19  Alan Modra  <amodra@gmail.com>
 
        * config/obj-elf.c (obj_elf_section): Cater for TC_KEEP_OPERAND_SPACES

diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index d6b8ecb..4760c05 100644 (file)
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -15005,7 +15005,10 @@ mips_after_parse_args (void)
     }
 
   if (arch_info == 0)
-    arch_info = mips_parse_cpu ("default CPU", MIPS_CPU_STRING_DEFAULT);
+    {
+      arch_info = mips_parse_cpu ("default CPU", MIPS_CPU_STRING_DEFAULT);
+      gas_assert (arch_info);
+    }
 
   if (ABI_NEEDS_64BIT_REGS (mips_abi) && !ISA_HAS_64BIT_REGS (arch_info->isa))
     as_bad (_("-march=%s is not compatible with the selected ABI"),