dtrace discuss - Mar 2009 - func() builtin does not resolve correctly on unix module

Hi,

I have been facing an issue with the "func()" builtin on a PC (Program
Counter) which is part of the "unix" module''s text.

The dtrace script that I use is as follows (extended from the example
provided in
http://blogs.sun.com/jonh/entry/performance_counter_generic_events)

#!/usr/sbin/dtrace -Fs

inline int UNIX_MOD_START = 0xFFFFFFFFFB800000;
inline int UNIX_MOD_END = 0xFFFFFFFFFB99D986;

inline int GENUNIX_MOD_START = 0xFFFFFFFFFB921CD0;
inline int GENUNIX_MOD_END = 0xFFFFFFFFFBBD2548;

inline int MAC_MOD_START = 0xFFFFFFFFFBB9B338;
inline int MAC_MOD_END = 0xFFFFFFFFFBBBEB00;

cpc:::PAPI_tot_cyc-kernel-5000
/arg0 >= UNIX_MOD_START && arg0 < UNIX_MOD_END/
{
         @unix[func(arg0)] = count();
}

cpc:::PAPI_tot_cyc-kernel-5000
/arg0 >= GENUNIX_MOD_START && arg0 < GENUNIX_MOD_END/
{
         @genunix[func(arg0)] = count();
}

cpc:::PAPI_tot_cyc-kernel-5000
/arg0 >= MAC_MOD_START && arg0 < MAC_MOD_END/
{
         @mac[func(arg0)] = count();
}

END
{
         trunc(@unix, 20);
         printa("%-50a %@d\n", @unix);

         trunc(@genunix, 20);
         printa("%-50a %@d\n", @genunix);

         trunc(@mac, 20);
         printa("%-50a %@d\n", @mac);
}

And given below is the output that I see:


unix`mutex_enter                                   802562
unix`ip_ocsum                                      2644713
unix`0xfffffffffb84                                2691253
^^^^^^^^^^^^^^^^^^^^^^
mac`mac_tx_fanout_mode                             31199
genunix`ddi_dma_sync                               3223

The unresolved address (unix`0xfffffffffb84) is my concern.
What function in "unix" does this correspond to? Is this a known
problem? If so, is there any solution/workaround to get to the actual
function this is referring to?

I have hit the very same address on 4 separate amd systems (Of course, I
have modified the _MOD_START and _MOD_END macros on each of these
systems as required). Given below is the uname output on some of them
(in case it is of any help):

bash-3.2# uname -srvmpi
SunOS 5.11 snv_109 i86pc i386 i86pc

bash-3.2# uname -srvmpi
SunOS 5.11 snv_110 i86pc i386 i86pc

TIA,
Pavan

Hi Pavan,
 
> And given below is the output that I see:
>
>
> unix`mutex_enter                                   802562
> unix`ip_ocsum                                      2644713
> unix`0xfffffffffb84                                2691253
> ^^^^^^^^^^^^^^^^^^^^^^
Usually when I see unresolved functions on amd it is typically in something
like patched bcopy code (there''s a whole bunch of jiggery-pokery
goes off in there). I assume you''ve truncated the address here as
it''s
missing a few characters? If so, try going back a few 100 bytes from
that and disassembling to see if you are near something that looks valid.

If you get no joy send me login details to a system and I''ll take a
look.

Jon.