New submission from Matthias Klose: <jakub> richi: https://github.com/nemomobile-packages/python3/blob/master/Modules/faulthandler.c#L903 <polacek> richi: LD_LIBRARY_PATH=/builddir/build/BUILD/Python-3.4.2/build/debug/ /builddir/build/BUILD/Python-3.4.2/build/debug/python -E -c 'import faulthandler; faulthandler.enable(); faulthandler._stack_overflow()' <polacek> i.e. what Jakub says <jakub> richi: the function certainly shouldn't return address of a local variable; dunno what would happen if you just cast that to an integer though <jakub> richi: and it better should do something to avoid tail calls there <jakub> richi: the if (sp < min_sp || max_sp < sp) is also undefined behavior <richi> ah, I get python segfaults building some extensions instead (but can't reproduce locally...) <richi> jakub: so what's your fix? <jakub> richi: I don't have a fix, we just documented it not to be a gcc fault, we'll leave fixing to the package maintainer <richi> ah, I see <jakub> richi: dunno if e.g. uintptr_t x; memcpy (&x, &sp, sizeof (x)); would DTRT and be portable enough <jakub> richi: and then of course pass uintptr_t min_sp/max_sp, compare the x against that etc. <richi> well, just (uintptr_t)&buffer should be enough
---------- components: Extension Modules messages: 235685 nosy: doko priority: normal severity: normal status: open title: undefined behaviour in faulthandler.c, exposed by GCC 5 type: crash versions: Python 3.4, Python 3.5 _______________________________________ Python tracker <rep...@bugs.python.org> <http://bugs.python.org/issue23433> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
