[issue24851] infinite loop in faulthandler._stack_overflow

Change by Irit Katriel : -- stage: -> resolved status: pending -> closed ___ Python tracker ___ ___ Python-bugs-list mailing list

[issue24851] infinite loop in faulthandler._stack_overflow

Irit Katriel added the comment: I think this was fixed in issue38965. -- nosy: +iritkatriel, ned.deily resolution: -> duplicate status: open -> pending superseder: -> test_stack_overflow (test.test_faulthandler.FaultHandlerTests) is stuck with GCC10

[issue24851] infinite loop in faulthandler._stack_overflow

Change by Xi Ruoyao : -- versions: +Python 3.7 ___ Python tracker ___ ___ Python-bugs-list mailing list Unsubscribe:

[issue24851] infinite loop in faulthandler._stack_overflow

Ronald Oussoren added the comment: GCC has a pragma and function attributes for changing the optimisation flags, that could be used to disable the tail call optimazation here. Something like the following (using a pragma): #pragma GCC push_options #pragma GCC optimize

[issue24851] infinite loop in faulthandler._stack_overflow

Paul Murphy added the comment: ... #pragma GCC optimize (no-optimize-sibling-calls) ... Does preserve the desired behavior under -O2 and -O3, probably a bit nicer than using O0. -- ___ Python tracker rep...@bugs.python.org

[issue24851] infinite loop in faulthandler._stack_overflow

Antoine Pitrou added the comment: To fix this in a generic way, perhaps the function could update a volatile global variable after the recursive call? -- nosy: +pitrou ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue24851

[issue24851] infinite loop in faulthandler._stack_overflow

Paul Murphy added the comment: Somehow, you need to preserve access to the stack memory. The generated code is still growing the stack, it just fails to touch any of it. I'm guessing a volatile access would just add an extra non-stack access to the infinite loop. Initially, I had tried

[issue24851] infinite loop in faulthandler._stack_overflow

Antoine Pitrou added the comment: Initially, I had tried creating a non-inlined function to touch the stack memory. It worked in this case, but still required some undesirable compiler specific assistance. Hmm... store the non-inlined function's pointer in a volatile global, and call that

[issue24851] infinite loop in faulthandler._stack_overflow

New submission from Paul Murphy: This is a duplicate of Issue 23654, except it occurs on GCC 5.1 with -O2 when building for a ppc64le target. GCC is optimizes this as a tail call, removing the accesses to the unused stack variables. -- components: Extension Modules files:

[issue24851] infinite loop in faulthandler._stack_overflow

Changes by Yury Selivanov yseliva...@gmail.com: -- nosy: +haypo ___ Python tracker rep...@bugs.python.org http://bugs.python.org/issue24851 ___ ___ Python-bugs-list