diff options
| -rw-r--r-- | configure.ac | 2 | ||||
| -rw-r--r-- | vm_insnhelper.c | 12 |
2 files changed, 14 insertions, 0 deletions
diff --git a/configure.ac b/configure.ac index b77cbea545..a9c3796caa 100644 --- a/configure.ac +++ b/configure.ac @@ -1359,6 +1359,7 @@ AC_CHECK_HEADERS(ucontext.h) AC_CHECK_HEADERS(utime.h) AC_CHECK_HEADERS(sys/epoll.h) AC_CHECK_HEADERS(sys/event.h) +AC_CHECK_HEADERS(stdatomic.h) AS_CASE("$target_cpu", [x64|x86_64|i[3-6]86*], [ AC_CHECK_HEADERS(x86intrin.h) @@ -2039,6 +2040,7 @@ AC_CHECK_FUNCS(_longjmp) # used for AC_ARG_WITH(setjmp-type) test x$ac_cv_func__longjmp = xno && ac_cv_func__setjmp=no AC_CHECK_FUNCS(arc4random_buf) AC_CHECK_FUNCS(atan2l atan2f) +AC_CHECK_DECLS(atomic_signal_fence, [], [], [#include <stdatomic.h>]) AC_CHECK_FUNCS(chmod) AC_CHECK_FUNCS(chown) AC_CHECK_FUNCS(chroot) diff --git a/vm_insnhelper.c b/vm_insnhelper.c index b72167f75d..913fd86bb1 100644 --- a/vm_insnhelper.c +++ b/vm_insnhelper.c @@ -12,6 +12,10 @@ #include <math.h> +#ifdef HAVE_STDATOMIC_H + #include <stdatomic.h> +#endif + #include "constant.h" #include "debug_counter.h" #include "internal.h" @@ -388,6 +392,14 @@ vm_push_frame(rb_execution_context_t *ec, .jit_return = NULL }; + /* Ensure the initialization of `*cfp` above never gets reordered with the update of `ec->cfp` below. + This is a no-op in all cases we've looked at (https://godbolt.org/z/3oxd1446K), but should guarantee it for all + future/untested compilers/platforms. */ + + #ifdef HAVE_DECL_ATOMIC_SIGNAL_FENCE + atomic_signal_fence(memory_order_seq_cst); + #endif + ec->cfp = cfp; if (VMDEBUG == 2) { |