s390/extable: convert to relative table with data

Follow arm64, riscv, and x86 and change extable layout to common
"relative table with data". This allows to get rid of s390 specific
code in sorttable.c.

The main difference to before is that extable entries do not contain a
relative function pointer anymore. Instead data and type fields are
added.

The type field is used to indicate which exception handler needs to be
called, while the data field is currently unused.

Acked-by: Alexander Gordeev <agordeev@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>

1 files changed, 15 insertions, 6 deletions

diff --git a/arch/s390/mm/extable.c b/arch/s390/mm/extable.c
index d6ca75570dcf..ac6b736ac883 100644
--- a/arch/s390/mm/extable.c
+++ b/arch/s390/mm/extable.c
@@ -1,6 +1,8 @@
 // SPDX-License-Identifier: GPL-2.0
 
 #include <linux/extable.h>
+#include <linux/panic.h>
+#include <asm/asm-extable.h>
 #include <asm/extable.h>
 
 const struct exception_table_entry *s390_search_extables(unsigned long addr)
@@ -15,17 +17,24 @@ const struct exception_table_entry *s390_search_extables(unsigned long addr)
 	return search_extable(__start_amode31_ex_table, num, addr);
 }
 
+static bool ex_handler_fixup(const struct exception_table_entry *ex, struct pt_regs *regs)
+{
+	regs->psw.addr = extable_fixup(ex);
+	return true;
+}
+
 bool fixup_exception(struct pt_regs *regs)
 {
 	const struct exception_table_entry *ex;
-	ex_handler_t handler;
 
 	ex = s390_search_extables(instruction_pointer(regs));
 	if (!ex)
 		return false;
-	handler = ex_fixup_handler(ex);
-	if (unlikely(handler))
-		return handler(ex, regs);
-	regs->psw.addr = extable_fixup(ex);
-	return true;
+	switch (ex->type) {
+	case EX_TYPE_FIXUP:
+		return ex_handler_fixup(ex, regs);
+	case EX_TYPE_BPF:
+		return ex_handler_bpf(ex, regs);
+	}
+	panic("invalid exception table entry");
 }