Bad core files with 2.6.19-rc2

Bad core files with 2.6.19-rc2

[Steve Youngs]

gdb doesn't like any core dump file generated while running
2.6.19-rc2.  If I `kill -SIGSEGV $some_app_pid' and then...

  gdb some_app core

I get...

  warning: Couldn't find general-purpose registers in core file.
  #0  0x00000000 in ?? ()

But if I gdb attach to a running process and then kill -SIGSEGV
the process, it produces a normal trace without problem.


-- 
|---<Steve Youngs>---------------<GnuPG KeyID: A94B3003>---|
|                   Te audire no possum.                   |
|             Musa sapientum fixa est in aure.             |
|----------------------------------<steve@youngs.au.com>---|

Re: Bad core files with 2.6.19-rc2

[Adrian Bunk]

On Sun, Oct 15, 2006 at 12:53:41PM +1000, Steve Youngs wrote:

> gdb doesn't like any core dump file generated while running
> 2.6.19-rc2.  If I `kill -SIGSEGV $some_app_pid' and then...
> 
>   gdb some_app core
> 
> I get...
> 
>   warning: Couldn't find general-purpose registers in core file.
>   #0  0x00000000 in ?? ()
> 
> But if I gdb attach to a running process and then kill -SIGSEGV
> the process, it produces a normal trace without problem.

It seems this issue should be fixed in Linus' tree now.

Can you confirm it's fixed?

TIA
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed

Re: Bad core files with 2.6.19-rc2

[Petr Vandrovec]

Adrian Bunk wrote:
> On Sun, Oct 15, 2006 at 12:53:41PM +1000, Steve Youngs wrote:
> 
> 
>>gdb doesn't like any core dump file generated while running
>>2.6.19-rc2.  If I `kill -SIGSEGV $some_app_pid' and then...
>>
>>  gdb some_app core
>>
>>I get...
>>
>>  warning: Couldn't find general-purpose registers in core file.
>>  #0  0x00000000 in ?? ()
>>
>>But if I gdb attach to a running process and then kill -SIGSEGV
>>the process, it produces a normal trace without problem.
> 
> 
> It seems this issue should be fixed in Linus' tree now.
> 
> Can you confirm it's fixed?

It should be fixed now (i.e. 26 minutes ago).  Before my first fix core 
dump contained only some phdrs and notes, nothing else.  After first fix 
core dump contained everything, but pieces after notes were shifted down 
by couple of bytes.  After second fix I believe that cores are written 
out correctly - readelf still says that there is some zeroed note, but 
it seems to me like feature - older core files have this as well:

$ readelf -a core
...
Notes at offset 0x00035608 with length 0x00000018:
   Owner         Data size       Description
   Linux         0x00000004      Unknown note type: (0x00000000)

						Petr Vandrovec

Re: Bad core files with 2.6.19-rc2

[Steve Youngs]

* Petr Vandrovec <petr@vandrovec.name> writes:

  > Adrian Bunk wrote:
  >> On Sun, Oct 15, 2006 at 12:53:41PM +1000, Steve Youngs wrote:
  >>> warning: Couldn't find general-purpose registers in core file.
  >>> #0  0x00000000 in ?? ()

  >> It seems this issue should be fixed in Linus' tree now.
  >> 
  >> Can you confirm it's fixed?

  > It should be fixed now

Yes, it is.  Thank you very much.

-- 
|---<Steve Youngs>---------------<GnuPG KeyID: A94B3003>---|
|                   Te audire no possum.                   |
|             Musa sapientum fixa est in aure.             |
|----------------------------------<steve@youngs.au.com>---|