From b6d14daa1c48d8938a140a671bcd17cb40cdd54d Mon Sep 17 00:00:00 2001 From: Tim Peters Date: Wed, 19 Dec 2001 04:11:07 +0000 Subject: SF bug #494668: PUSH() should assert-fail on overflow. eval_frame(): Added asserts to the top of the eval loop, to verify that the eval stack pointer is in bounds, plus some comments. --- Python/ceval.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/Python/ceval.c b/Python/ceval.c index 94cf17e..2feb123 100644 --- a/Python/ceval.c +++ b/Python/ceval.c @@ -497,7 +497,7 @@ eval_frame(PyFrameObject *f) #ifdef DXPAIRS int lastopcode = 0; #endif - PyObject **stack_pointer; + PyObject **stack_pointer; /* Next free slot in value stack */ register unsigned char *next_instr; register int opcode=0; /* Current opcode */ register int oparg=0; /* Current opcode argument, if any */ @@ -586,7 +586,7 @@ eval_frame(PyFrameObject *f) next_instr = first_instr + f->f_lasti; stack_pointer = f->f_stacktop; assert(stack_pointer != NULL); - f->f_stacktop = NULL; + f->f_stacktop = NULL; /* remains NULL unless yield suspends frame */ if (tstate->use_tracing) { if (tstate->c_tracefunc != NULL) { @@ -634,6 +634,8 @@ eval_frame(PyFrameObject *f) w = NULL; for (;;) { + assert(stack_pointer >= f->f_valuestack); /* else underflow */ + assert(STACK_LEVEL() <= f->f_stacksize); /* else overflow */ /* Do periodic things. Doing this every time through the loop would add too much overhead, so we do it only every Nth instruction. We also do it if -- cgit v0.12