From ac827edc493d3ac3f5b9b0cc353df1d4b418a9aa Mon Sep 17 00:00:00 2001 From: Victor Stinner Date: Wed, 14 Aug 2019 23:35:27 +0200 Subject: bpo-21131: Fix faulthandler.register(chain=True) stack (GH-15276) faulthandler now allocates a dedicated stack of SIGSTKSZ*2 bytes, instead of just SIGSTKSZ bytes. Calling the previous signal handler in faulthandler signal handler uses more than SIGSTKSZ bytes of stack memory on some platforms. --- Misc/NEWS.d/next/Library/2019-08-14-15-34-23.bpo-21131.0MMQRi.rst | 4 ++++ Modules/faulthandler.c | 6 +++++- 2 files changed, 9 insertions(+), 1 deletion(-) create mode 100644 Misc/NEWS.d/next/Library/2019-08-14-15-34-23.bpo-21131.0MMQRi.rst diff --git a/Misc/NEWS.d/next/Library/2019-08-14-15-34-23.bpo-21131.0MMQRi.rst b/Misc/NEWS.d/next/Library/2019-08-14-15-34-23.bpo-21131.0MMQRi.rst new file mode 100644 index 0000000..d330aca --- /dev/null +++ b/Misc/NEWS.d/next/Library/2019-08-14-15-34-23.bpo-21131.0MMQRi.rst @@ -0,0 +1,4 @@ +Fix ``faulthandler.register(chain=True)`` stack. faulthandler now allocates a +dedicated stack of ``SIGSTKSZ*2`` bytes, instead of just ``SIGSTKSZ`` bytes. +Calling the previous signal handler in faulthandler signal handler uses more +than ``SIGSTKSZ`` bytes of stack memory on some platforms. diff --git a/Modules/faulthandler.c b/Modules/faulthandler.c index 2331051..5dbbcad 100644 --- a/Modules/faulthandler.c +++ b/Modules/faulthandler.c @@ -1325,7 +1325,11 @@ _PyFaulthandler_Init(int enable) * be able to allocate memory on the stack, even on a stack overflow. If it * fails, ignore the error. */ stack.ss_flags = 0; - stack.ss_size = SIGSTKSZ; + /* bpo-21131: allocate dedicated stack of SIGSTKSZ*2 bytes, instead of just + SIGSTKSZ bytes. Calling the previous signal handler in faulthandler + signal handler uses more than SIGSTKSZ bytes of stack memory on some + platforms. */ + stack.ss_size = SIGSTKSZ * 2; stack.ss_sp = PyMem_Malloc(stack.ss_size); if (stack.ss_sp != NULL) { err = sigaltstack(&stack, &old_stack); -- cgit v0.12