08-08-2005
memory stack problem
Hi, I am writing a C program under SCO Unix. I have a memory stack problem but do not know how to go about fixing it. I have tried running INSURE but that does not detect any problems.
Essentially the problem is that the memory address shifts on return from a routine. I pass a pointer to function "get_dsp_data" which passes a pointer to that pointer (AKA double pointer) to a database routine. In the db routine I fill in the double pointer structure after malloc'ing memory. The data is fine within the db routine. The data is fine in the "get_dsp_data" routine. However, when the data gets back to the first routine the memory location has shifted, see below.
*****************************************************
stbm.c 310 before: p_number_of_dsps is 0 and
&p_number_of_dsps is 2147481140
stbm.c 1052 In get_dsp_data, p_number_of_dsps is 16 and
&p_number_of_dsps is 2147481140
** memory shifts here but I don't know why or how **
stbm.c 312 after: p_number_of_dsps is 0 and
&p_number_of_dsps is 2147481034
*****************************************************
If I change things around so that the variable is a global then the program cores at the end of the last routine before exit. I am thinking that possibly memory is going past its bounds but I don't know how to verify or fix this.
One other bit of information, I ported my code over to LINUX and ran valgrind on it, but no problems were detected. But that could be because the memory did not shift when run on the LINUX system. Perhaps it is a difference in the way the compilers handle memory??
Please if anyone has any ideas for me on how to troubleshoot let me know.
Thanks, Jeanne
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