Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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_MITIGATION_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 $NR of them
11 * @__VA_ARGS__: arguments for @f
12 *
13 * Avoid retpoline overhead for known builtin, checking @f vs each of them and
14 * eventually invoking directly the builtin function. The functions are checked
15 * in the given order. Fallback to the indirect call.
16 */
17#define INDIRECT_CALL_1(f, f1, ...) \
18 ({ \
19 typeof(f) __f1 = (f); \
20 likely(__f1 == f1) ? f1(__VA_ARGS__) : __f1(__VA_ARGS__); \
21 })
22#define INDIRECT_CALL_2(f, f2, f1, ...) \
23 ({ \
24 typeof(f) __f2 = (f); \
25 likely(__f2 == f2) ? f2(__VA_ARGS__) : \
26 INDIRECT_CALL_1(__f2, f1, __VA_ARGS__); \
27 })
28#define INDIRECT_CALL_3(f, f3, f2, f1, ...) \
29 ({ \
30 typeof(f) __f3 = (f); \
31 likely(__f3 == f3) ? f3(__VA_ARGS__) : \
32 INDIRECT_CALL_2(__f3, f2, f1, __VA_ARGS__); \
33 })
34#define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) \
35 ({ \
36 typeof(f) __f4 = (f); \
37 likely(__f4 == f4) ? f4(__VA_ARGS__) : \
38 INDIRECT_CALL_3(__f4, f3, f2, f1, __VA_ARGS__); \
39 })
40
41#define INDIRECT_CALLABLE_DECLARE(f) f
42#define INDIRECT_CALLABLE_SCOPE
43#define EXPORT_INDIRECT_CALLABLE(f) EXPORT_SYMBOL(f)
44
45#else
46#define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__)
47#define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__)
48#define INDIRECT_CALL_3(f, f3, f2, f1, ...) f(__VA_ARGS__)
49#define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__)
50#define INDIRECT_CALLABLE_DECLARE(f)
51#define INDIRECT_CALLABLE_SCOPE static
52#define EXPORT_INDIRECT_CALLABLE(f)
53#endif
54
55/*
56 * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is
57 * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6
58 * alternatives
59 */
60#if IS_ENABLED(CONFIG_IPV6)
61#define INDIRECT_CALL_INET(f, f2, f1, ...) \
62 INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__)
63#elif IS_ENABLED(CONFIG_INET)
64#define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
65#else
66#define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__)
67#endif
68
69#if IS_ENABLED(CONFIG_INET)
70#define INDIRECT_CALL_INET_1(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__)
71#else
72#define INDIRECT_CALL_INET_1(f, f1, ...) f(__VA_ARGS__)
73#endif
74
75#endif