[Bug c/13182] -fstack-check probes too distant when allocating on stack

Tue Nov 25 13:02:00 GMT 2003

------- Additional Comments From schneck at math dot berkeley dot edu  2003-11-25 13:02 -------
(In reply to comment #1)

I fear you may have missed my point.

Stack probes are supposed to happen at STACK_CHECK_PROBE_INTERVAL,
i.e. 4096.

One function does one probe, at sp - 12792 (which is > 4096*3).
One function does two probes, one at sp - 4392,
the other at sp - 12792 (a difference of > 4096*2).

Even if the thread has TWO guard pages this could fail
to be safe!

Please forgive me if I misunderstand.  I had looked at the
internals manual, and I understand (I think) why it is
correct for the first check to be at sp - 4392.
But I am rather convinced that the interval had better
be 4096 (or less) thereafter.

Robert

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|RESOLVED                    |UNCONFIRMED
         Resolution|INVALID                     |

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=13182