c6x: Move EXCEPTION_TABLE to RO_DATA segment

Since the EXCEPTION_TABLE is read-only, collapse it into RO_DATA.
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Aurelien Jacquiot <jacquiot.aurelien@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: linux-alpha@vger.kernel.org
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-c6x-dev@linux-c6x.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Cc: Mark Salter <msalter@redhat.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Rick Edgecombe <rick.p.edgecombe@intel.com>
Cc: Segher Boessenkool <segher@kernel.crashing.org>
Cc: Will Deacon <will@kernel.org>
Cc: x86-ml <x86@kernel.org>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: https://lkml.kernel.org/r/20191029211351.13243-20-keescook@chromium.org

arch/c6x/kernel/vmlinux.lds.S

@@ -5,6 +5,9 @@
  *  Copyright (C) 2010, 2011 Texas Instruments Incorporated
  *  Mark Salter <msalter@redhat.com>
  */
+
+#define RO_EXCEPTION_TABLE_ALIGN	16
+
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/thread_info.h>
 #include <asm/page.h>
@@ -80,8 +83,6 @@ SECTIONS
 		*(.gnu.warning)
 	}
 
-	EXCEPTION_TABLE(16)
-
 	RO_DATA(PAGE_SIZE)
 	.const :
 	{