| Olivier Deprez | 92d4c21 | 2022-12-06 15:05:30 +0100 | [diff] [blame^] | 1 | /* SPDX-License-Identifier: LGPL-2.1-only OR MIT */ |
| 2 | /* |
| 3 | * rseq/compiler.h |
| 4 | * |
| 5 | * Work-around asm goto compiler bugs. |
| 6 | * |
| 7 | * (C) Copyright 2021 - Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 8 | */ |
| 9 | |
| 10 | #ifndef RSEQ_COMPILER_H |
| 11 | #define RSEQ_COMPILER_H |
| 12 | |
| 13 | /* |
| 14 | * gcc prior to 4.8.2 miscompiles asm goto. |
| 15 | * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58670 |
| 16 | * |
| 17 | * gcc prior to 8.1.0 miscompiles asm goto at O1. |
| 18 | * https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103908 |
| 19 | * |
| 20 | * clang prior to version 13.0.1 miscompiles asm goto at O2. |
| 21 | * https://github.com/llvm/llvm-project/issues/52735 |
| 22 | * |
| 23 | * Work around these issues by adding a volatile inline asm with |
| 24 | * memory clobber in the fallthrough after the asm goto and at each |
| 25 | * label target. Emit this for all compilers in case other similar |
| 26 | * issues are found in the future. |
| 27 | */ |
| 28 | #define rseq_after_asm_goto() asm volatile ("" : : : "memory") |
| 29 | |
| 30 | #endif /* RSEQ_COMPILER_H_ */ |