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| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2021-03-03-17-58-49.bpo-43390.epPpwV.rst | 6 | ||||
| -rw-r--r-- | Python/pylifecycle.c | 5 |
2 files changed, 10 insertions, 1 deletions
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-03-03-17-58-49.bpo-43390.epPpwV.rst b/Misc/NEWS.d/next/Core and Builtins/2021-03-03-17-58-49.bpo-43390.epPpwV.rst new file mode 100644 index 0000000..ae115db --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2021-03-03-17-58-49.bpo-43390.epPpwV.rst @@ -0,0 +1,6 @@ +CPython now sets the ``SA_ONSTACK`` flag in ``PyOS_setsig`` for the VM's +default signal handlers. This is friendlier to other in-process code that +an extension module or embedding use could pull in (such as Golang's cgo) +where tiny thread stacks are the norm and ``sigaltstack()`` has been used to +provide for signal handlers. This is a no-op change for the vast majority +of processes that don't use sigaltstack. diff --git a/Python/pylifecycle.c b/Python/pylifecycle.c index ec77084..d03c6c0 100644 --- a/Python/pylifecycle.c +++ b/Python/pylifecycle.c @@ -2884,7 +2884,10 @@ PyOS_setsig(int sig, PyOS_sighandler_t handler) struct sigaction context, ocontext; context.sa_handler = handler; sigemptyset(&context.sa_mask); - context.sa_flags = 0; + /* Using SA_ONSTACK is friendlier to other C/C++/Golang-VM code that + * extension module or embedding code may use where tiny thread stacks + * are used. https://bugs.python.org/issue43390 */ + context.sa_flags = SA_ONSTACK; if (sigaction(sig, &context, &ocontext) == -1) return SIG_ERR; return ocontext.sa_handler; |