Re: [OMPI devel] Possible buffer overrun bug in opal_free_list_grow, called by MPI::Init

2008-10-21 Thread Stephan Kramer
at 1:43 PM, Stephan Kramer wrote: George Bosilca wrote: Stephan, You might be right. intptr_t is a signed type, which allows the result of % to be potentially negative. However, on the other side, mod is defined as a size_t which [based on my memory] is definitively unsigned as it represent a s

Re: [OMPI devel] Possible buffer overrun bug in opal_free_list_grow, called by MPI::Init

2008-10-19 Thread Stephan Kramer
ber gets wrapped in the assignment to the signed integer mod: UINT_MAX+1-x - in the subtraction CACHE_LINE_SIZE-mod, the result is wrapped around again, giving CACHE_LINE_SIZE+x Cheers Stephan On Oct 16, 2008, at 7:29 PM, Stephan Kramer wrote: George Bosilca wrote: I did investigate this i

Re: [OMPI devel] Possible buffer overrun bug in opal_free_list_grow, called by MPI::Init

2008-10-16 Thread Stephan Kramer
appear in the subsequent element loop. This is confirmed with the output of some debugging statements I've pasted below. Also I haven't come across the same bug on 64bit machines. I guess this should be uintptr_t instead? Cheers Stephan Kramer The debugging output: mpidebug: num

Re: [OMPI devel] Possible buffer overrun bug in opal_free_list_grow, called by MPI::Init

2008-10-14 Thread Stephan Kramer
uffer. Any help would be much appreciated Stephan Kramer Patrick, I'm unable to reproduce the buffer overrun with the latest trunk. I run valgrind (with the memchekcer tool) on a regular basis on the trunk, and I never noticed anything like that. Moreover, I went over the code, and I canno