news about retrieving kernel symbols (tasklist_struct)

news about retrieving kernel symbols (tasklist_struct)

[Giacomo]

Good afternoon.
As to the need to retrieve the symbol tasklist_lock, which is no more
exported in kernel 2.6.18, i tried to use the

kallsyms_lookup_name("tasklist_lock");

function.

It returns an unsigned long which should be the address of the symbol,
e.g. the variable tasklist_lock.



So i tried to use it, but it does not work!

-------------------------------------------------------------------
rwlock_t tasklist_lock_from_symbol;
unsigned long tlockptr;

tlockptr =  kallsyms_lookup_name("tasklist_lock");

if( tlockptr == 0)
	return NULL;

printk("symbol: 0x%lx\n",  tlockptr);

memcpy(&tasklist_lock_from_symbol, (void*) &tlockptr, sizeof(rwlock_t) );

read_lock(&tasklist_lock_from_symbol);
(...)
---------------------------------------------------------------------

Perhaps this is not the right way to retrieve the address of the variable...

thanks a lot


-- 
Giacomo S.
http://www.giacomos.it

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Re: news about retrieving kernel symbols (tasklist_struct)

[Patrick McHardy]

Giacomo wrote:
> Good afternoon.
> As to the need to retrieve the symbol tasklist_lock, which is no more
> exported in kernel 2.6.18, i tried to use the

There is a reason why it is not exported anymore. You can't use
it from netfilter.