name : indirect_call_wrapper.h /* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_INDIRECT_CALL_WRAPPER_H #define _LINUX_INDIRECT_CALL_WRAPPER_H #ifdef CONFIG_RETPOLINE /* * INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin * @f: function pointer * @f$NR: builtin functions names, up to $NR of them * @__VA_ARGS__: arguments for @f * * Avoid retpoline overhead for known builtin, checking @f vs each of them and * eventually invoking directly the builtin function. The functions are checked * in the given order. Fallback to the indirect call. */ #define INDIRECT_CALL_1(f, f1, ...) \ ({ \ likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \ }) #define INDIRECT_CALL_2(f, f2, f1, ...) \ ({ \ likely(f == f2) ? f2(__VA_ARGS__) : \ INDIRECT_CALL_1(f, f1, __VA_ARGS__); \ }) #define INDIRECT_CALL_3(f, f3, f2, f1, ...) \ ({ \ likely(f == f3) ? f3(__VA_ARGS__) : \ INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__); \ }) #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) \ ({ \ likely(f == f4) ? f4(__VA_ARGS__) : \ INDIRECT_CALL_3(f, f3, f2, f1, __VA_ARGS__); \ }) #define INDIRECT_CALLABLE_DECLARE(f) f #define INDIRECT_CALLABLE_SCOPE #define EXPORT_INDIRECT_CALLABLE(f) EXPORT_SYMBOL(f) #else #define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__) #define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__) #define INDIRECT_CALL_3(f, f3, f2, f1, ...) f(__VA_ARGS__) #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__) #define INDIRECT_CALLABLE_DECLARE(f) #define INDIRECT_CALLABLE_SCOPE static #define EXPORT_INDIRECT_CALLABLE(f) #endif /* * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6 * alternatives */ #if IS_BUILTIN(CONFIG_IPV6) #define INDIRECT_CALL_INET(f, f2, f1, ...) \ INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__) #elif IS_ENABLED(CONFIG_INET) #define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) #else #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) #endif #if IS_ENABLED(CONFIG_INET) #define INDIRECT_CALL_INET_1(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) #else #define INDIRECT_CALL_INET_1(f, f1, ...) f(__VA_ARGS__) #endif #endif