| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
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| 2 | #ifndef _LINUX_INDIRECT_CALL_WRAPPER_H |
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| 3 | #define _LINUX_INDIRECT_CALL_WRAPPER_H |
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| 4 | |
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| 5 | #ifdef CONFIG_MITIGATION_RETPOLINE |
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| 6 | |
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| 7 | /* |
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| 8 | * INDIRECT_CALL_$NR - wrapper for indirect calls with $NR known builtin |
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| 9 | * @f: function pointer |
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| 10 | * @f$NR: builtin functions names, up to $NR of them |
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| 11 | * @__VA_ARGS__: arguments for @f |
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| 12 | * |
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| 13 | * Avoid retpoline overhead for known builtin, checking @f vs each of them and |
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| 14 | * eventually invoking directly the builtin function. The functions are checked |
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| 15 | * in the given order. Fallback to the indirect call. |
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| 16 | */ |
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| 17 | #define INDIRECT_CALL_1(f, f1, ...) \ |
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| 18 | ({ \ |
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| 19 | likely(f == f1) ? f1(__VA_ARGS__) : f(__VA_ARGS__); \ |
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| 20 | }) |
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| 21 | #define INDIRECT_CALL_2(f, f2, f1, ...) \ |
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| 22 | ({ \ |
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| 23 | likely(f == f2) ? f2(__VA_ARGS__) : \ |
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| 24 | INDIRECT_CALL_1(f, f1, __VA_ARGS__); \ |
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| 25 | }) |
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| 26 | #define INDIRECT_CALL_3(f, f3, f2, f1, ...) \ |
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| 27 | ({ \ |
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| 28 | likely(f == f3) ? f3(__VA_ARGS__) : \ |
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| 29 | INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__); \ |
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| 30 | }) |
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| 31 | #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) \ |
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| 32 | ({ \ |
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| 33 | likely(f == f4) ? f4(__VA_ARGS__) : \ |
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| 34 | INDIRECT_CALL_3(f, f3, f2, f1, __VA_ARGS__); \ |
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| 35 | }) |
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| 36 | |
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| 37 | #define INDIRECT_CALLABLE_DECLARE(f) f |
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| 38 | #define INDIRECT_CALLABLE_SCOPE |
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| 39 | #define EXPORT_INDIRECT_CALLABLE(f) EXPORT_SYMBOL(f) |
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| 40 | |
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| 41 | #else |
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| 42 | #define INDIRECT_CALL_1(f, f1, ...) f(__VA_ARGS__) |
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| 43 | #define INDIRECT_CALL_2(f, f2, f1, ...) f(__VA_ARGS__) |
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| 44 | #define INDIRECT_CALL_3(f, f3, f2, f1, ...) f(__VA_ARGS__) |
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| 45 | #define INDIRECT_CALL_4(f, f4, f3, f2, f1, ...) f(__VA_ARGS__) |
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| 46 | #define INDIRECT_CALLABLE_DECLARE(f) |
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| 47 | #define INDIRECT_CALLABLE_SCOPE static |
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| 48 | #define EXPORT_INDIRECT_CALLABLE(f) |
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| 49 | #endif |
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| 50 | |
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| 51 | /* |
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| 52 | * We can use INDIRECT_CALL_$NR for ipv6 related functions only if ipv6 is |
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| 53 | * builtin, this macro simplify dealing with indirect calls with only ipv4/ipv6 |
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| 54 | * alternatives |
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| 55 | */ |
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| 56 | #if IS_BUILTIN(CONFIG_IPV6) |
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| 57 | #define INDIRECT_CALL_INET(f, f2, f1, ...) \ |
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| 58 | INDIRECT_CALL_2(f, f2, f1, __VA_ARGS__) |
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| 59 | #elif IS_ENABLED(CONFIG_INET) |
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| 60 | #define INDIRECT_CALL_INET(f, f2, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) |
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| 61 | #else |
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| 62 | #define INDIRECT_CALL_INET(f, f2, f1, ...) f(__VA_ARGS__) |
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| 63 | #endif |
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| 64 | |
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| 65 | #if IS_ENABLED(CONFIG_INET) |
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| 66 | #define INDIRECT_CALL_INET_1(f, f1, ...) INDIRECT_CALL_1(f, f1, __VA_ARGS__) |
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| 67 | #else |
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| 68 | #define INDIRECT_CALL_INET_1(f, f1, ...) f(__VA_ARGS__) |
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| 69 | #endif |
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| 70 | |
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| 71 | #endif |
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| 72 | |
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