[Crash-utility] Symbol info from System.map vs. DLKM-debuginfo

[Alex Sidorenko]

Hi Dave,

while working on an NFS problem (Ubuntu/Hardy) I needed to get definitions 
of 'struct svc_cacherep'. I have compiled nfsd.ko with debugging for an older 
kernel.

Current kernel: 2.6.24-24-generic
nfsd.ko:	2.6.24-21-generic

The definition of 'struct svc_cacherep' is the same. To avoid rebuilding 
nfsd.ko I decided to specify /boot/System.map-2.6.24-generic explicitly. 
Before loading 'nfsd.ko' the address of 'lru_cache' variable is correct, but 
after loading old nfsd.ko it changes:

crash32> sym lru_head
f908b988 (b) lru_head
crash32> mod -s nfsd /usr/lib/debug/lib/modules/2.6.24-21-generic/nfsd.ko
 MODULE   NAME                    SIZE  OBJECT FILE
f908a280  nfsd                  
228976  /usr/lib/debug/lib/modules/2.6.24-21-generic/nfsd.ko
crash32> sym lru_head
f908b984 (b) lru_head

Is this expected? It would be nice to be able to give precedence to symbols as 
defined in System.map (maybe a startup option or internal set option).

Regards,
Alex

-- 
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Alexandre Sidorenko             email: asid at hp.com
WTEC Linux			Hewlett-Packard (Canada)
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