https://github.com/python/cpython/commit/8934bb0c3179e4c020cd6f08dea64bccbf5... commit: 8934bb0c3179e4c020cd6f08dea64bccbf56ffa2 branch: 3.6 author: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> committer: ned-deily <nad@python.org> date: 2021-08-31T02:24:50-04:00 summary: bpo-38965: Fix faulthandler._stack_overflow() on GCC 10 (GH-17467) (GH-28079) Use the "volatile" keyword to prevent tail call optimization on any compiler, rather than relying on compiler specific pragma. (cherry picked from commit 8b787964e0a647caa0558b7c29ae501470d727d9) Co-authored-by: Victor Stinner <vstinner@python.org> (cherry picked from commit 5044c889dfced2f43e2cccb673d889a4882f6b3b) Co-authored-by: Miss Islington (bot) <31488909+miss-islington@users.noreply.github.com> files: A Misc/NEWS.d/next/Tests/2019-12-04-17-08-55.bpo-38965.yqax3m.rst M Modules/faulthandler.c diff --git a/Misc/NEWS.d/next/Tests/2019-12-04-17-08-55.bpo-38965.yqax3m.rst b/Misc/NEWS.d/next/Tests/2019-12-04-17-08-55.bpo-38965.yqax3m.rst new file mode 100644 index 0000000000000..517a1371eacd9 --- /dev/null +++ b/Misc/NEWS.d/next/Tests/2019-12-04-17-08-55.bpo-38965.yqax3m.rst @@ -0,0 +1,3 @@ +Fix test_faulthandler on GCC 10. Use the "volatile" keyword in +``faulthandler._stack_overflow()`` to prevent tail call optimization on any +compiler, rather than relying on compiler specific pragma. diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c index 890c64577cec1..3e0a7b127d4c7 100644 --- a/Modules/faulthandler.c +++ b/Modules/faulthandler.c @@ -1091,18 +1091,14 @@ faulthandler_fatal_error_py(PyObject *self, PyObject *args) #if defined(HAVE_SIGALTSTACK) && defined(HAVE_SIGACTION) #define FAULTHANDLER_STACK_OVERFLOW -#ifdef __INTEL_COMPILER - /* Issue #23654: Turn off ICC's tail call optimization for the - * stack_overflow generator. ICC turns the recursive tail call into - * a loop. */ -# pragma intel optimization_level 0 -#endif -static -uintptr_t +static uintptr_t stack_overflow(uintptr_t min_sp, uintptr_t max_sp, size_t *depth) { - /* allocate 4096 bytes on the stack at each call */ - unsigned char buffer[4096]; + /* Allocate (at least) 4096 bytes on the stack at each call. + + bpo-23654, bpo-38965: use volatile keyword to prevent tail call + optimization. */ + volatile unsigned char buffer[4096]; uintptr_t sp = (uintptr_t)&buffer; *depth += 1; if (sp < min_sp || max_sp < sp)