Re: dtrace + fbt provider

[Stathis Kamperis <ekamperi%gmail.com@localhost>]

2010/3/25 Darran Hunt <darran%netbsd.org@localhost>:
>
> On 25/03/2010, at 9:01 AM, Stathis Kamperis wrote:
>
>>>> Hey Darran; first million thanks for your work on porting DTrace :)
>>>>
>>>> Second, I can update the wiki page, don't waste time on such mundane
>>>> tasks.
>>>>
>>>> Third, I get a 100% reproducible kernel panic, every time I use an fbt
>>>> entry point.
>>>> http://leaf.dragonflybsd.org/~beket/dtrace.png
>>>>
>>>> It doesn't matter which function I hook into, the system will crash
>>>> instantaneously.
>>>> Unfortunately, I don't have a swap partition (epic fail), so I can't
>>>> set up a dump device and provide you a core.
>>>>
>>>> Mind that netbsd is running as virtualbox guest in an opensolaris host.
>>>>
>>>> Again, thanks for your work.
>>>>
>>>> Best regards,
>>>> Stathis
>>>
>>> Hi Stathis,
>>>
>>> thanks for trying this out!
>>>
>>> After a second look at the crash you have I think it is definitely a bug
>>> I
>>> have detecting that there is no CTF section available for the kernel.
>>>  This
>>> happens if your /boot (secondary boot) file has not been updated.  If you
>>> copy in a new boot from <dest>/i386/usr/mdec/boot to your root filesystem
>>> this should fix the crash.  I'll work on better detecting the problem and
>>> handling it without a crash.
>>>
>>> Best regards,
>>> Darran.
>>>
>>>
>>>
>>
>> Hi Darran,
>>
>> thanks for taking time to comment/bother.
>>
>> Unfortunately, I can still reproduce the panic. I did a cvs update
>> -dPA, build/install'ed kernel & distrubution sets, copied /boot file
>> from usr/mdec/boot to /boot.
>> I did it twice, but I'll give it another try in case I missed something.
>>
>>
>> Cheers,
>> Stathis
>
> Can you send me the output of readelf -S /netbsd?  I'd like to verify that
> you have .SUNW_ctf section as the last section.
>
> Cheers,
> Darran.
>
>

I don't think I have it. Here is the output of readelf -S /netbsd:

There are 30 section headers, starting at offset 0x948698:

Section Headers:
  [Nr] Name              Type            Addr     Off    Size   ES Flg Lk Inf Al
  [ 0]                   NULL            00000000 000000 000000 00      0   0  0
  [ 1] .text             PROGBITS        c0100000 001000 5e386c 00  AX  0   0 64
  [ 2] .rodata           PROGBITS        c06e3880 5e4880 2b5388 00   A  0   0 32
  [ 3] link_set_malloc_t PROGBITS        c0998c08 899c08 00010c 00   A  0   0  4
  [ 4] link_set_sysctl_f PROGBITS        c0998d14 899d14 0000d0 00   A  0   0  4
  [ 5] link_set_ah_rfs   PROGBITS        c0998de4 899de4 00001c 00   A  0   0  4
  [ 6] link_set_ah_chips PROGBITS        c0998e00 899e00 000014 00   A  0   0  4
  [ 7] link_set_domains  PROGBITS        c0998e14 899e14 000020 00   A  0   0  4
  [ 8] link_set_modules  PROGBITS        c0998e34 899e34 000018 00   A  0   0  4
  [ 9] link_set_bufq_str PROGBITS        c0998e4c 899e4c 000010 00   A  0   0  4
  [10] link_set_evcnts   PROGBITS        c0998e5c 899e5c 000028 00   A  0   0  4
  [11] link_set_dkwedge_ PROGBITS        c0998e84 899e84 000008 00   A  0   0  4
  [12] link_set_ieee8021 PROGBITS        c0998e8c 899e8c 000010 00   A  0   0  4
  [13] link_set_prop_lin PROGBITS        c0998e9c 899e9c 000020 00   A  0   0  4
  [14] .data             PROGBITS        c099a000 89a000 078cd4 00  WA
 0   0 4096
  [15] .bss              NOBITS          c0a12d00 912cd4 0c3cfc 00  WA  0   0 64
  [16] .note.netbsd.iden NOTE            c0ad69fc 912cd4 000018 00      0   0  4
  [17] .ident            PROGBITS        00000000 912cec 0144ed 00      0   0  1
  [18] .comment          PROGBITS        00000000 9271d9 01881a 00      0   0  1
  [19] .debug_abbrev     PROGBITS        00000000 93f9f3 000228 00      0   0  1
  [20] .debug_info       PROGBITS        00000000 93fc1b 0056fd 00      0   0  1
  [21] .debug_line       PROGBITS        00000000 945318 000387 00      0   0  1
  [22] .debug_frame      PROGBITS        00000000 9456a0 00002c 00      0   0  4
  [23] .debug_loc        PROGBITS        00000000 9456cc 00002c 00      0   0  1
  [24] .debug_pubnames   PROGBITS        00000000 9456f8 00002a 00      0   0  1
  [25] .debug_aranges    PROGBITS        00000000 945722 000020 00      0   0  1
  [26] .debug_str        PROGBITS        00000000 945742 002dbd 01  MS  0   0  1
  [27] .shstrtab         STRTAB          00000000 9484ff 000197 00      0   0  1
  [28] .symtab           SYMTAB          00000000 948b48 074f80 10
29 15073  4
  [29] .strtab           STRTAB          00000000 9bdac8 0716dc 00      0   0  1
Key to Flags:
  W (write), A (alloc), X (execute), M (merge), S (strings)
  I (info), L (link order), G (group), x (unknown)
  O (extra OS processing required) o (OS specific), p (processor specific)


Sorry for wasting your time, but I'd really like to get my hands dirty
with DTrace :)
Feel free to respond at a time of your convenience. No hurrys.


Best regards,
Stathis