registration error (rc -22) on a standard function. Why ?

registration error (rc -22) on a standard function. Why ?

[Breno Leitao]

Hi, 

I am trying to probe a function which was static and inline. To probe
it, I remove the static and inline modifier, to turn into a standard
function, but now I am getting the following error: 

WARNING: probe module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") registration error (rc -22)

Here is the function:

void _lock_tx_hashtbl(struct bonding *bond)
{
        spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
}

stap -p2 shows: 

module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") /* pc=.text+0x9b00 */ /* <- module("bonding").function("_lock_tx_hashtbl") */


Objdump shows: 

0000000000009b00 <._lock_tx_hashtbl>:
    9b00:       7c 08 02 a6     mflr    r0
    9b04:       38 63 01 f0     addi    r3,r3,496
    9b08:       f8 01 00 10     std     r0,16(r1)
    9b0c:       f8 21 ff 91     stdu    r1,-112(r1)
    9b10:       48 00 00 01     bl      9b10 <._lock_tx_hashtbl+0x10>
                        9b10: R_PPC64_REL24     ._spin_lock_bh
    9b14:       60 00 00 00     nop
    9b18:       38 21 00 70     addi    r1,r1,112
    9b1c:       e8 01 00 10     ld      r0,16(r1)
    9b20:       7c 08 03 a6     mtlr    r0
    9b24:       4e 80 00 20     blr


I really didn't understand why I can't probe that function. Any idea 
what might be wrong ?

Thanks
Breno

Re: registration error (rc -22) on a standard function. Why ?

[Ananth N Mavinakayanahalli]

On Wed, Dec 03, 2008 at 10:55:30PM -0200, Breno Leitao wrote:
> Hi, 
> 
> I am trying to probe a function which was static and inline. To probe
> it, I remove the static and inline modifier, to turn into a standard
> function, but now I am getting the following error: 
> 
> WARNING: probe module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") registration error (rc -22)
> 
> Here is the function:
> 
> void _lock_tx_hashtbl(struct bonding *bond)
> {
>         spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
> }
> 
> stap -p2 shows: 
> 
> module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") /* pc=.text+0x9b00 */ /* <- module("bonding").function("_lock_tx_hashtbl") */
> 
> 
> Objdump shows: 
> 
> 0000000000009b00 <._lock_tx_hashtbl>:
>     9b00:       7c 08 02 a6     mflr    r0
>     9b04:       38 63 01 f0     addi    r3,r3,496
>     9b08:       f8 01 00 10     std     r0,16(r1)
>     9b0c:       f8 21 ff 91     stdu    r1,-112(r1)
>     9b10:       48 00 00 01     bl      9b10 <._lock_tx_hashtbl+0x10>
>                         9b10: R_PPC64_REL24     ._spin_lock_bh
>     9b14:       60 00 00 00     nop
>     9b18:       38 21 00 70     addi    r1,r1,112
>     9b1c:       e8 01 00 10     ld      r0,16(r1)
>     9b20:       7c 08 03 a6     mtlr    r0
>     9b24:       4e 80 00 20     blr
> 
> 
> I really didn't understand why I can't probe that function. Any idea 
> what might be wrong ?

Possibly part of the SystemTap blacklist. For safety reasons we don't
allow probing certain routines (spinlock*, mutex*, atomic*) and this
looks to be one of them.

Try stap -vv and you'll see a more descriptive error.

Ananth

Re: registration error (rc -22) on a standard function. Why ?

[Frank Ch. Eigler]

Ananth N Mavinakayanahalli <ananth@in.ibm.com> writes:

> [...]
>> WARNING: probe module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") registration error (rc -22)
>> [...]
> Possibly part of the SystemTap blacklist. [...]

No; the systemtap blacklist takes effect early during pass 2. 
This was a pass 5 error.

- FChE

Re: registration error (rc -22) on a standard function. Why ?

[Srikar Dronamraju]

* Breno Leitao <leitao@linux.vnet.ibm.com> [2008-12-03 22:55:30]:

Hi Breno, 

Can you if there are related messages in dmesg when you see this error?

-Srikar

> Hi, 
> 
> I am trying to probe a function which was static and inline. To probe
> it, I remove the static and inline modifier, to turn into a standard
> function, but now I am getting the following error: 
> 
> WARNING: probe module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") registration error (rc -22)
> 
> Here is the function:
> 
> void _lock_tx_hashtbl(struct bonding *bond)
> {
>         spin_lock_bh(&(BOND_ALB_INFO(bond).tx_hashtbl_lock));
> }
> 
> stap -p2 shows: 
> 
> module("bonding").function("_lock_tx_hashtbl@drivers/net/bonding/bond_alb.c:132") /* pc=.text+0x9b00 */ /* <- module("bonding").function("_lock_tx_hashtbl") */
> 
> 
> Objdump shows: 
> 
> 0000000000009b00 <._lock_tx_hashtbl>:
>     9b00:       7c 08 02 a6     mflr    r0
>     9b04:       38 63 01 f0     addi    r3,r3,496
>     9b08:       f8 01 00 10     std     r0,16(r1)
>     9b0c:       f8 21 ff 91     stdu    r1,-112(r1)
>     9b10:       48 00 00 01     bl      9b10 <._lock_tx_hashtbl+0x10>
>                         9b10: R_PPC64_REL24     ._spin_lock_bh
>     9b14:       60 00 00 00     nop
>     9b18:       38 21 00 70     addi    r1,r1,112
>     9b1c:       e8 01 00 10     ld      r0,16(r1)
>     9b20:       7c 08 03 a6     mtlr    r0
>     9b24:       4e 80 00 20     blr
> 
> 
> I really didn't understand why I can't probe that function. Any idea 
> what might be wrong ?
> 
> Thanks
> Breno