[PATCH v2 7/8] klp-build: Add LoongArch syscall patching macro

[George Guo <dongtai.guo@linux.dev>]

From: George Guo <guodongtai@kylinos.cn>

Add LoongArch support for KLP_SYSCALL_DEFINEx(), mirroring the generic
__SYSCALL_DEFINEx() pattern from include/linux/syscalls.h.

Co-developed-by: Kexin Liu <liukexin@kylinos.cn>
Signed-off-by: Kexin Liu <liukexin@kylinos.cn>
Signed-off-by: George Guo <guodongtai@kylinos.cn>
---
 include/linux/livepatch_helpers.h | 22 ++++++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/include/linux/livepatch_helpers.h b/include/linux/livepatch_helpers.h
index 4b647b83865f..a8aad067177b 100644
--- a/include/linux/livepatch_helpers.h
+++ b/include/linux/livepatch_helpers.h
@@ -91,6 +91,28 @@
 	}								\
 	static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
 
+#elif defined(CONFIG_LOONGARCH)
+
+#define __KLP_SYSCALL_DEFINEx(x, name, ...)                             \
+	__diag_push();                                                  \
+	__diag_ignore(GCC, 8, "-Wattribute-alias",                      \
+		      "Type aliasing is used to sanitize syscall arguments");\
+	asmlinkage long sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))       \
+		__attribute__((alias(__stringify(__se_sys##name))));    \
+	ALLOW_ERROR_INJECTION(sys##name, ERRNO);                        \
+	static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__));\
+	asmlinkage long __se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__)); \
+	asmlinkage long __attribute__((optimize("-fno-optimize-sibling-calls")))\
+			__se_sys##name(__MAP(x,__SC_LONG,__VA_ARGS__))  \
+	{                                                               \
+		long ret = __klp_do_sys##name(__MAP(x,__SC_CAST,__VA_ARGS__));\
+		__MAP(x,__SC_TEST,__VA_ARGS__);                         \
+		__PROTECT(x, ret,__MAP(x,__SC_ARGS,__VA_ARGS__));       \
+		return ret;                                             \
+	}                                                               \
+	__diag_pop();                                                   \
+	static inline long __klp_do_sys##name(__MAP(x,__SC_DECL,__VA_ARGS__))
+
 #endif
 
 #endif /* _LINUX_LIVEPATCH_HELPERS_H */
-- 
2.25.1