Re: fedora rawhide problems with kprobes/debuginfo addresses

[Roland McGrath <roland at redhat dot com>]

> Not very sure exactly what information you are looking for. But I am
> assuming you are looking for run time virtual and physical address of the
> kernel.

The virtual address, yes.  The physical address is not especially helpful
unless I know how to convert it to a kernel virtual address (in userland).
The lower and upper bounds are nice to have, as well as just the offset.

> For virtual address you can grab _text or _stext. 

This is essentially what I'm doing with:

awk 'NF > 3 { print a; exit 0 } { a=$1 } NR==1 { print a }' /proc/kallsyms 

> Alternatively you can parse /proc/kcore and look for ELF header where
> kernel is mapped.

Sorry, I don't follow what you are suggesting here.  (Also, /proc/kcore is
privileged which is a new inconvenience we don't want.)  In kcore I find
out where all the memory is in virtual addresses, but I don't see how that
tells me what part of it is the kernel image.

> Dave Anderson is already parsing /proc/kcore for determining kernel
> virtual address in "crash" for x86_64  

I didn't find any code in crash-4.0 that looks at /proc/kcore.


Thanks,
Roland