s390/exceptions: switch to relative exception table entries

This is the s390 port of 70627654 "x86, extable: Switch to relative
exception table entries".
Reduces the size of our exception tables by 50% on 64 bit builds.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

2 files changed, 38 insertions, 19 deletions

diff --git a/arch/s390/include/asm/processor.h b/arch/s390/include/asm/processor.h
index 7e81ff17a89b..f3e0aabfc6bc 100644
--- a/arch/s390/include/asm/processor.h
+++ b/arch/s390/include/asm/processor.h
@@ -11,6 +11,8 @@
 #ifndef __ASM_S390_PROCESSOR_H
 #define __ASM_S390_PROCESSOR_H
 
+#ifndef __ASSEMBLY__
+
 #include <linux/linkage.h>
 #include <linux/irqflags.h>
 #include <asm/cpu.h>
@@ -348,23 +350,6 @@ extern void (*s390_base_ext_handler_fn)(void);
 
 #define ARCH_LOW_ADDRESS_LIMIT  0x7fffffffUL
 
-/*
- * Helper macro for exception table entries
- */
-#ifndef CONFIG_64BIT
-#define EX_TABLE(_fault,_target)                        \
-        ".section __ex_table,\"a\"\n"                   \
-        "       .align 4\n"                             \
-        "       .long  " #_fault "," #_target "\n"      \
-        ".previous\n"
-#else
-#define EX_TABLE(_fault,_target)                        \
-        ".section __ex_table,\"a\"\n"                   \
-        "       .align 8\n"                             \
-        "       .quad  " #_fault "," #_target "\n"      \
-        ".previous\n"
-#endif
-
 extern int memcpy_real(void *, void *, size_t);
 extern void memcpy_absolute(void *, void *, size_t);
 
@@ -375,4 +360,25 @@ extern void memcpy_absolute(void *, void *, size_t);
         memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));        \
 }
 
-#endif                                 /* __ASM_S390_PROCESSOR_H           */
+/*
+ * Helper macro for exception table entries
+ */
+#define EX_TABLE(_fault, _target)       \
+        ".section __ex_table,\"a\"\n"   \
+        ".align 4\n"                    \
+        ".long  (" #_fault ") - .\n"    \
+        ".long  (" #_target ") - .\n"   \
+        ".previous\n"
+
+#else /* __ASSEMBLY__ */
+
+#define EX_TABLE(_fault, _target)       \
+        .section __ex_table,"a" ;       \
+        .align  4 ;                     \
+        .long   (_fault) - . ;          \
+        .long   (_target) - . ;         \
+        .previous
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* __ASM_S390_PROCESSOR_H */
diff --git a/arch/s390/include/asm/uaccess.h b/arch/s390/include/asm/uaccess.h
index a8ab18b18b54..34268df959a3 100644
--- a/arch/s390/include/asm/uaccess.h
+++ b/arch/s390/include/asm/uaccess.h
@@ -76,9 +76,22 @@ static inline int __range_ok(unsigned long addr, unsigned long size)
 
 struct exception_table_entry
 {
-        unsigned long insn, fixup;
+        int insn, fixup;
 };
 
+static inline unsigned long extable_insn(const struct exception_table_entry *x)
+{
+        return (unsigned long)&x->insn + x->insn;
+}
+
+static inline unsigned long extable_fixup(const struct exception_table_entry *x)
+{
+        return (unsigned long)&x->fixup + x->fixup;
+}
+
+#define ARCH_HAS_SORT_EXTABLE
+#define ARCH_HAS_SEARCH_EXTABLE
+
 struct uaccess_ops {
         size_t (*copy_from_user)(size_t, const void __user *, void *);
         size_t (*copy_from_user_small)(size_t, const void __user *, void *);