[Crash-utility] [PATCH] Fix for "kmem <addr>" for kernels configured with CONFIG_SLUB and SLAB_RED_ZONE.

[OGAWA Hirofumi]

Dave Anderson <anderson at redhat.com> writes:

>> I see what you say. However, my usual usage of kmem is to get the data
>> address of object (I was thinking the most users are same usage).
>> 
>> 	crash> kmem <pointer in stack>
>> 	info for data address
>> 
>> 	copy & paste <data address>
>> 	crash> p *(struct inode *)<data address>
>
> Why not copy-and-paste the address from <pointer in stack>?  Or use "bt -FF"
> to get the kmem cache type, and skip using "kmem" entirely?  ;-)

Yes, bt -FF helps much. However, the pointer in stack is address in
middle of object data in many times.

E.g. for ext4_inode_cache, "struct address_space *" is in stack. But
actual slab object is inode->i_mapping == ext4_inode_info.vfs_inode.i_data.
Or functions takes member of object, e.g., &object->list.

If there is easy way to get the object address from the field of object
address, it would be what I want.

Thanks.
-- 
OGAWA Hirofumi <hirofumi at mail.parknet.co.jp>