LoongArch: extable: Add `type` and `data` fields

This is a LoongArch port of commit d6e2cc564775 ("arm64: extable: add
`type` and `data` fields").

Subsequent patches will add specialized handlers for fixups, in addition
to the simple PC fixup we have today. In preparation, this patch adds a
new `type` field to struct exception_table_entry, and uses this to
distinguish the fixup and other cases. A `data` field is also added so
that subsequent patches can associate data specific to each exception
site (e.g. register numbers).

Handlers are named ex_handler_*() for consistency, following the example
of x86. At the same time, get_ex_fixup() is split out into a helper so
that it can be used by other ex_handler_*() functions in the subsequent
patches.

Signed-off-by: Youling Tang <tangyouling@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 6 insertions, 1 deletions

diff --git a/arch/loongarch/mm/extable.c b/arch/loongarch/mm/extable.c
index 08a9a7d6357a..fd2395221cff 100644
--- a/arch/loongarch/mm/extable.c
+++ b/arch/loongarch/mm/extable.c
@@ -30,5 +30,10 @@ bool fixup_exception(struct pt_regs *regs)
 	if (!ex)
 		return false;
 
-	return ex_handler_fixup(ex, regs);
+	switch (ex->type) {
+	case EX_TYPE_FIXUP:
+		return ex_handler_fixup(ex, regs);
+	}
+
+	BUG();
 }