New submission from Xi Ruoyao <xry...@mengyan1223.wang>:
In faulthandler.c STACK_OVERFLOW_MAX_SIZE is defined to 100 * 1024 * 1024 (100MB). But recently KPTI has been applied to mitigate Meltdown (CVE-2017-5754) so the userspace stack pointer may be very close to 0xffffffff on Linux systems with 32-bit x86. For example, on my laptop it's sometimes 0xffffcc20. So the expression sp + STACK_OVERFLOW_MAX_SIZE overflows and becomes a very small number. That causes faulthandler._stack_overflow() to bail out after only one recursive call: Traceback (most recent call last): File "<string>", line 1, in <module> RuntimeError: unable to raise a stack overflow (allocated 4124 bytes on the stack, 1 recursive calls) ---------- components: Extension Modules messages: 341915 nosy: xry111 priority: normal severity: normal status: open title: faulthandler._stack_overflow doesn't work on x86-linux with KPTI enabled type: behavior versions: Python 3.7 _______________________________________ Python tracker <rep...@bugs.python.org> <https://bugs.python.org/issue36856> _______________________________________ _______________________________________________ Python-bugs-list mailing list Unsubscribe: https://mail.python.org/mailman/options/python-bugs-list/archive%40mail-archive.com
