Re: 4.15.14 crash with iscsi target and dvd

From: Bart Van Assche
Date: Sat Apr 07 2018 - 13:09:13 EST


On Sat, 2018-04-07 at 12:53 -0400, Wakko Warner wrote:
> Bart Van Assche wrote:
> > On Thu, 2018-04-05 at 22:06 -0400, Wakko Warner wrote:
> > > I know now why scsi_print_command isn't doing anything. cmd->cmnd is null.
> > > I added a dev_printk in scsi_print_command where the 2 if statements return.
> > > Logs:
> > > [ 29.866415] sr 3:0:0:0: cmd->cmnd is NULL
> >
> > That's something that should never happen. As one can see in
> > scsi_setup_scsi_cmnd() and scsi_setup_fs_cmnd() both functions initialize
> > that pointer. Since I have not yet been able to reproduce myself what you
> > reported, would it be possible for you to bisect this issue? You will need
> > to follow something like the following procedure (see also
> > https://git-scm.com/docs/git-bisect):
>
> After doing 3 successful compiles with good/bad, I got this error and was
> not able to compile any more kernels:
> CC scripts/mod/devicetable-offsets.s
> scripts/mod/empty.c:1:0: error: code model kernel does not support PIC mode
> /* empty file to figure out endianness / word size */
>
> scripts/mod/devicetable-offsets.c:1:0: error: code model kernel does not support PIC mode
> #include <linux/kbuild.h>
>
> scripts/Makefile.build:153: recipe for target 'scripts/mod/devicetable-offsets.s' failed
>
> I don't think it found the bad commit.

Have you tried to modify the kernel Makefile as indicated in the following
e-mail? This should make the kernel build:

https://lists.ubuntu.com/archives/kernel-team/2016-May/077178.html

Thanks,

Bart.