Red Hat Bugzilla – Bug 154796
Missing /dev/kmem, cannot read from kernel virtual memory.
Last modified: 2015-01-04 17:18:50 EST
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User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6) Gecko/20040510
Description of problem:
We need to access kernel virtual memory and we do it through /dev/kmem.
But there is no /dev/kmem in the above mentioned kernel series.
We need /proc/kallsyms also, so that we can get the address (in the kernel
virtual memory) of a symbol from it and then go to that offset in /dev/kmem
to get the symbol.
In short, we need both /dev/kmem and /proc/kallsyms to be present.
Do we need to follow certain steps for /dev/kmem to get created when the
If either of these is not going to be provided by RedHat, then could you
please suggest alternatives?
Version-Release number of selected component (if applicable):
2.6.9-5.EL, 2.6.9-6.26.ELsmp (amongst others of the same series)
Steps to Reproduce:
1. Install RHEL4 by an FTP installation. Just follow the steps as promted.
2. Find that /dev/kmem does not exist.
This is an issue on i686 as well as x86_64.
/dev/kmem support was intentionally removed, as it served no practical purpose
other than to serve as a potential security problem (by allowing root users to
modify kernel memory), or to enable binary module drivers to access
structures/functions they shouldn't be touching.
Only use exported functions.