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1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef _LINUX_INDIRECT_CALL_WRAPPER_H | |
3 | #define _LINUX_INDIRECT_CALL_WRAPPER_H | |
4 | ||
5 | #ifdef CONFIG_RETPOLINE | |
6 | ||
7 | /* | |
8 | * INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin | |
9 | * @f: function pointer | |
10 | * @f$NR: builtin functions names, up to $NR of them | |
11 | * @__VA_ARGS__: arguments for @f | |
12 | * | |
13 | * Avoid retpoline overhead for known builtin, checking @f vs each of them and | |
14 | * eventually invoking directly the builtin function. The functions are check | |
15 | * in the given order. Fallback to the indirect call. | |
16 | */ | |
17 | #define INDIRECT_CALL_1(f, f1, ...) \ | |
18 | ({ \ | |
19 | likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \ | |
20 | }) | |
21 | #define INDIRECT_CALL_2(f, f2, f1, ...) \ | |
22 | ({ \ | |
23 | likely(f == f2) ? f2(__VA_ARGS__) : \ | |
24 | INDIRECT_CALL_1(f, f1, __VA_ARGS__); \ | |
25 | }) | |
26 | ||
27 | #define INDIRECT_CALLABLE_DECLARE(f) f | |
28 | #define INDIRECT_CALLABLE_SCOPE | |
29 | ||
30 | #else | |
c03b0358 PA |
31 | #define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__) |
32 | #define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__) | |
283c16a2 PA |
33 | #define INDIRECT_CALLABLE_DECLARE(f) |
34 | #define INDIRECT_CALLABLE_SCOPE static | |
35 | #endif | |
36 | ||
37 | /* | |
38 | * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is | |
39 | * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6 | |
40 | * alternatives | |
41 | */ | |
42 | #if IS_BUILTIN(CONFIG_IPV6) | |
43 | #define INDIRECT_CALL_INET(f, f2, f1, ...) \ | |
44 | INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__) | |
45 | #elif IS_ENABLED(CONFIG_INET) | |
46 | #define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) | |
47 | #else | |
48 | #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) | |
49 | #endif | |
50 | ||
51 | #endif |