From 4173d677a1d7c72bb32d292fbff1b4cf073d615c Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Thu, 3 Mar 2022 21:45:01 +0100 Subject: bpo-46913: Fix test_faulthandler.test_sigfpe() on UBSAN (GH-31662) Disable undefined behavior sanitizer (UBSAN) on faulthandler_sigfpe(). --- .../Tests/2022-03-03-17-36-24.bpo-46913.vxETIE.rst | 3 +++ Modules/faulthandler.c | 22 ++++++++++++++++++++-- 2 files changed, 23 insertions(+), 2 deletions(-) create mode 100644 Misc/NEWS.d/next/Tests/2022-03-03-17-36-24.bpo-46913.vxETIE.rst diff --git a/Misc/NEWS.d/next/Tests/2022-03-03-17-36-24.bpo-46913.vxETIE.rst b/Misc/NEWS.d/next/Tests/2022-03-03-17-36-24.bpo-46913.vxETIE.rst new file mode 100644 index 0000000..65fed1c --- /dev/null +++ b/Misc/NEWS.d/next/Tests/2022-03-03-17-36-24.bpo-46913.vxETIE.rst @@ -0,0 +1,3 @@ +Fix test_faulthandler.test_sigfpe() if Python is built with undefined +behavior sanitizer (UBSAN): disable UBSAN on the faulthandler_sigfpe() +function. Patch by Victor Stinner. diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c index 46e18c1..4f9f661 100644 --- a/Modules/faulthandler.c +++ b/Modules/faulthandler.c @@ -1102,17 +1102,35 @@ faulthandler_fatal_error_c_thread(PyObject *self, PyObject *args) Py_RETURN_NONE; } -static PyObject * +// clang uses __attribute__((no_sanitize("undefined"))) +// GCC 4.9+ uses __attribute__((no_sanitize_undefined)) +#if defined(__has_feature) // Clang +# if __has_feature(undefined_behavior_sanitizer) +# define _Py_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize("undefined"))) +# endif +#endif +#if defined(__GNUC__) \ + && ((__GNUC__ >= 5) || (__GNUC__ == 4) && (__GNUC_MINOR__ >= 9)) +# define _Py_NO_SANITIZE_UNDEFINED __attribute__((no_sanitize_undefined)) +#endif +#ifndef _Py_NO_SANITIZE_UNDEFINED +# define _Py_NO_SANITIZE_UNDEFINED +#endif + +static PyObject* _Py_NO_SANITIZE_UNDEFINED faulthandler_sigfpe(PyObject *self, PyObject *args) { + faulthandler_suppress_crash_report(); + /* Do an integer division by zero: raise a SIGFPE on Intel CPU, but not on PowerPC. Use volatile to disable compile-time optimizations. */ volatile int x = 1, y = 0, z; - faulthandler_suppress_crash_report(); z = x / y; + /* If the division by zero didn't raise a SIGFPE (e.g. on PowerPC), raise it manually. */ raise(SIGFPE); + /* This line is never reached, but we pretend to make something with z to silence a compiler warning. */ return PyLong_FromLong(z); -- cgit v0.12