parisc: Use generic extable search and sort routines

Switch to the generic extable search and sort routines which were introduced
with commit a272858 from Ard Biesheuvel. This saves quite some memory in the
vmlinux binary with the 64bit kernel.

Signed-off-by: Helge Deller <deller@gmx.de>
(cherry picked from commit 0de798584bdedfdad19db21e3c7aec84f252f4f3)
Signed-off-by: Alex Shi <alex.shi@linaro.org>

Author: hdeller

arch/parisc/Kconfig

@@ -11,6 +11,7 @@ config PARISC
 	select RTC_DRV_GENERIC
 	select INIT_ALL_POSSIBLE
 	select BUG
+	select BUILDTIME_EXTABLE_SORT
 	select HAVE_PERF_EVENTS
 	select GENERIC_ATOMIC64 if !64BIT
 	select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE

arch/parisc/include/asm/assembly.h

@@ -523,7 +523,7 @@
 	 */
 #define ASM_EXCEPTIONTABLE_ENTRY(fault_addr, except_addr)	\
 	.section __ex_table,"aw"			!	\
-	ASM_ULONG_INSN	fault_addr, except_addr		!	\
+	.word (fault_addr - .), (except_addr - .)	!	\
 	.previous
 
 

arch/parisc/include/asm/uaccess.h

@@ -60,14 +60,15 @@ static inline long access_ok(int type, const void __user * addr,
  * use a 32bit (unsigned int) address here.
  */
 
+#define ARCH_HAS_RELATIVE_EXTABLE
 struct exception_table_entry {
-	unsigned long insn;	/* address of insn that is allowed to fault. */
-	unsigned long fixup;	/* fixup routine */
+	int insn;	/* relative address of insn that is allowed to fault. */
+	int fixup;	/* relative address of fixup routine */
 };
 
 #define ASM_EXCEPTIONTABLE_ENTRY( fault_addr, except_addr )\
 	".section __ex_table,\"aw\"\n"			   \
-	ASM_WORD_INSN #fault_addr ", " #except_addr "\n\t" \
+	".word (" #fault_addr " - .), (" #except_addr " - .)\n\t" \
 	".previous\n"
 
 /*

arch/parisc/mm/fault.c

@@ -140,12 +140,6 @@ int fixup_exception(struct pt_regs *regs)
 {
 	const struct exception_table_entry *fix;
 
-	/* If we only stored 32bit addresses in the exception table we can drop
-	 * out if we faulted on a 64bit address. */
-	if ((sizeof(regs->iaoq[0]) > sizeof(fix->insn))
-		&& (regs->iaoq[0] >> 32))
-			return 0;
-
 	fix = search_exception_tables(regs->iaoq[0]);
 	if (fix) {
 		struct exception_data *d;
@@ -155,7 +149,8 @@ int fixup_exception(struct pt_regs *regs)
 		d->fault_space = regs->isr;
 		d->fault_addr = regs->ior;
 
-		regs->iaoq[0] = ((fix->fixup) & ~3);
+		regs->iaoq[0] = (unsigned long)&fix->fixup + fix->fixup;
+		regs->iaoq[0] &= ~3;
 		/*
 		 * NOTE: In some cases the faulting instruction
 		 * may be in the delay slot of a branch. We

scripts/sortextable.c

@@ -283,6 +283,7 @@ do_file(char const *const fname)
 	case EM_X86_64:
 	case EM_S390:
 	case EM_AARCH64:
+	case EM_PARISC:
 		custom_sort = sort_relative_table;
 		break;
 	case EM_ARCOMPACT: