Re: kern/57833: kernel panic on xorg exit

[Ramiro Aceves <ea1abz%gmail.com@localhost>]

El 13/1/24 a las 1:40, David H. Gutteridge escribió:
> The following reply was made to PR kern/57833; it has been noted by GNATS.
>
> From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
> To: Gnats Bugs <gnats-bugs%netbsd.org@localhost>
> Cc: Taylor R Campbell <riastradh%netbsd.org@localhost>
> Subject: Re: kern/57833: kernel panic on xorg exit
> Date: Fri, 12 Jan 2024 19:37:16 -0500
>
>   On 2024-01-12 17:52, Ramiro Aceves wrote:
>   > El 12/1/24 a las 0:05, David H. Gutteridge escribió:
>   >
>   >> The following reply was made to PR kern/57833; it has been noted by
>   >> GNATS.
>   >>
>   >> From: "David H. Gutteridge" <david%gutteridge.ca@localhost>
>   >> To: Taylor R Campbell <riastradh%netbsd.org@localhost>
>   >> Cc: gnats-bugs%netbsd.org@localhost
>   >> Subject: Re: kern/57833: kernel panic on xorg exit
>   >> Date: Thu, 11 Jan 2024 18:04:44 -0500
>   >>
>   >> --=_79cd473ca3d4e19fbe52c232ee5dd792
>   >> Content-Transfer-Encoding: 7bit
>   >> Content-Type: text/plain; charset=US-ASCII;
>   >> format=flowed
>   >> On 2024-01-10 23:37, Taylor R Campbell wrote:
>   >>> Can you also try the attached patch, instead of the other one, to see
>   >>> what happens?
>   >>>
>   >>> (This might break things more spectacularly -- I haven't thought
>   >>> about
>   >>> whether it makes a lot of sense -- but it should at least prevent the
>   >>> particular crash you observed, if we ever get that far with it.)
>   >> I've supplied a debug log. (It can be found at:
>   >> https://www.netbsd.org/~gutteridge/pr57833_debug.log .)
>   >> Applying the first (small) patch did not prevent the panics. But the
>   >> larger patch did fix the problem for me. There was a slight coding
>   >> error with the second patch (wrong label for a goto statement), so it
>   >> didn't compile as-is. I've attached a revised patch that fixes that
>   >> one
>   >> line, should anyone else want to test this.
>   >> Thanks,
>   >> Dave
>   >
>   > Hello Dave, thanks for feedback. Here I had the same problem, I applied
>   > the patch and could not compile the kernel  because en error in 555
>   > line when compiling i915_gem_stolen.c file. I changed
>   >
>   > goto err;
>   >
>   > to
>   >
>   > goto out;
>   >
>   > (not sure if that is the right fix)
>   
>   Yes, it is.
>   
>   > File compiled ok. Rebuilt the kernel and I had the same panic the first
>   > time abandoned Xorg session.
>   
>   There must be something different about your hardware than mine here,
>   then. (Mine is Intel 945GME.) The patch did work for me, but I guess
>   there's more to it.


Hello Dave, thanks for your help.

Yes, there must be sometihng different between my system and yours. I 
have notice something since I use the patched kernel. I do not know if 
it is related or not, but /var/crash/netbsd.4.gz file cannot be extracted.

netbsd-compal# cd /var/crash/
netbsd-compal# ls -al
total 1904080
drwxrwx---   2 root  wheel        512 Jan 13 10:57 .
drwxr-xr-x  26 root  wheel        512 Jan  9 19:14 ..
-rw-------   1 root  wheel          2 Jan 13 10:56 bounds
-rw-------   1 root  wheel          5 Jan  1 15:04 minfree
-rw-------   1 root  wheel    1958710 Jan  9 19:21 netbsd.0
-rw-------   1 root  wheel  154079764 Jan  9 19:21 netbsd.0.core
-rw-------   1 root  wheel    1958710 Jan  9 19:24 netbsd.1
-rw-------   1 root  wheel  117210132 Jan  9 19:24 netbsd.1.core
-rw-------   1 root  wheel    1958710 Jan  9 20:14 netbsd.2
-rw-------   1 root  wheel  202709524 Jan  9 20:14 netbsd.2.core
-rw-------   1 root  wheel    1958710 Jan 10 07:18 netbsd.3
-rw-------   1 root  wheel  245231124 Jan 10 07:18 netbsd.3.core
-rw-------   1 root  wheel  122661396 Jan 12 19:29 netbsd.4.core
-rw-------   1 root  wheel     843776 Jan 12 19:29 netbsd.4.gz
-rw-------   1 root  wheel  122661396 Jan 13 10:56 netbsd.5.core
-rw-------   1 root  wheel     843776 Jan 13 10:56 netbsd.5.

Look at this. 0, 1, 2 and 3 are the crashes with the GENERIC kernel. I 
started xorg ONLY ONCE and when exiting, the panic was produced.


netbsd-compal# gunzip netbsd.4.gz
gunzip: netbsd.4.gz: unexpected end of file
gunzip: netbsd.4.gz: uncompress failed

And whent to bed.

Today I started the operating system but I did not entered in Xorg, but 
at boot the system tried to save netbsd.5.gz and I could see a segfault 
on the screen. In the same way, netbsd.5.gz could not be extracted.

netbsd-compal# gunzip netbsd.5.gz
gunzip: netbsd.5.gz: unexpected end of file
gunzip: netbsd.5.gz: uncompress failed



>   
>   Do you have a build that includes a netbsd.gdb file? If not, you can
>   generate one (e.g., for your patched kernel) by un-commenting the
>   line
>   
>   makeoptions	DEBUG="-g"

I am compiling now, lets wait to see what happens. This old machine 
takes 32 minutes to compile the kernel without debugging symbols. With 
them, I do not know. I am very newbie to all of this but it is fun and a 
good learning experience!
>   
>   in your kernel config file (I assume GENERIC?) and re-building. The
>   extra file should appear.

Yes, I use GENERIC renamed to MYKERNEL as the guide says :-)

>   
>   Then we would have the means to get the other details Taylor is looking
>   for here (see the email from Thu, 11 Jan 2024 03:45UTC).

ok.

>   
>   Dave
>   
>   PS Sorry I was not able to send you a patch again earlier. GMail is not
>   accepting email from my domain, so my email bounced. Evidently my emails
>   do make it when funnelled through GNATS.

No problem. I had indeed a bad experience with gmail. I downloaded 
Taylor patches using Thunderbird and they ended in DOS format instead of 
UNIX. Patching failed in a very strange manner, but beeing a newbie I 
thought I did not know how to patch a file. I were struggling my mind 
several hours searching on the internet until Vim said that the file was 
in DOS format. I changed format to UNIX and patches were applied fine 
using inside /usr/src:

patch -p1 <patch.file

Also noticed that Gmail marks as spam many emails addreses of netbsd 
users. I do not know...

Ramiro.