| 1 | /* SPDX-License-Identifier: (GPL-2.0 or LGPL-2.1) |
| 2 | * |
| 3 | * wrapper/compiler.h |
| 4 | * |
| 5 | * Copyright (C) 2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com> |
| 6 | */ |
| 7 | |
| 8 | #ifndef _LTTNG_WRAPPER_COMPILER_H |
| 9 | #define _LTTNG_WRAPPER_COMPILER_H |
| 10 | |
| 11 | #include <linux/compiler.h> |
| 12 | |
| 13 | /* |
| 14 | * Don't allow compiling with buggy compiler. |
| 15 | */ |
| 16 | |
| 17 | #ifdef GCC_VERSION |
| 18 | |
| 19 | /* |
| 20 | * http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58854 |
| 21 | */ |
| 22 | # ifdef __ARMEL__ |
| 23 | # if GCC_VERSION >= 40800 && GCC_VERSION <= 40802 |
| 24 | # error Your gcc version produces clobbered frame accesses |
| 25 | # endif |
| 26 | # endif |
| 27 | #endif |
| 28 | |
| 29 | /* |
| 30 | * READ/WRITE_ONCE were introduced in kernel 3.19 and ACCESS_ONCE |
| 31 | * was removed in 4.15. Prefer READ/WRITE but fallback to ACCESS |
| 32 | * when they are not available. |
| 33 | */ |
| 34 | #ifndef READ_ONCE |
| 35 | # define READ_ONCE(x) ACCESS_ONCE(x) |
| 36 | #endif |
| 37 | |
| 38 | #ifndef WRITE_ONCE |
| 39 | # define WRITE_ONCE(x, val) ({ ACCESS_ONCE(x) = val; }) |
| 40 | #endif |
| 41 | |
| 42 | #endif /* _LTTNG_WRAPPER_COMPILER_H */ |