Diagnosing Memory Heap Corruption in glibc with MALLOC_CHECK_
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Setting MALLOC_CHECK_ :
- If MALLOC_CHECK_ is set to 0 (zero), the memory management functions are simply more tolerant of error but do not give warnings.
- Maybe be useful if we are prevented from finding one memory bug by another that is not convenient to fix at the moment; it might allow us to use other tools to chase down the other memory bug.
- It may also be useful if you are running code that works on another system but not on Linux and we want a quick workaround that may allow the code to function temporarily, before you have the chance to resolve the error.
- If MALLOC_CHECK_ is set to 1 (one), the memory management functions print out warning messages on standard error when they notice problems.
- It is useful if we are not aware of any problems and just want to be notified if any problem exist.
- If MALLOC_CHECK_ is set to 2 (two), the memory management functions call abort()when they notice problems.
- This is most useful from inside the debugger or a shell starting an application or daemon, because it allows you to get a backtrace as soon as the memory management functions discover the error, which will get us closest to the point at which the error has happened.
- It is useful if we get a core caused by a memory corruption, we would have more information about memory allocation therefore, making things better for troubleshooting where we need to find out which application overwrote a memory address.
- We can still combine settings 1 and 2 and MALLOC_CHECK_ is set to 3 (three), where it will print out the warning messages on standard error (1) and will call abort() when problems are noticed (2).
1. Add the following to the /etc/init.d/pre_ndsd_start file:
- NAMCD script (/etc/init.d/namcd):
# Template configuration variables
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- Document ID:3113982
- Creation Date:11-MAR-08
- Modified Date:27-APR-12
- NovellOpen Enterprise Server
- SUSESUSE Linux Enterprise Server
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