[LTP] ❌ FAIL: Test report for kernel 5.3.9-rc1-dfe283e.cki (stable)

[Greg KH]

On Mon, Nov 04, 2019 at 09:28:10AM -0500, Jan Stancek wrote:
> 
> 
> ----- Original Message -----
> > On Mon, Nov 04, 2019 at 08:35:51AM -0500, Jan Stancek wrote:
> > > 
> > > 
> > > ----- Original Message -----
> > > > 
> > > > Hello,
> > > > 
> > > > We ran automated tests on a recent commit from this kernel tree:
> > > > 
> > > >        Kernel repo:
> > > >        git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git
> > > >             Commit: dfe283e9fdac - Linux 5.3.9-rc1
> > > > 
> > > > The results of these automated tests are provided below.
> > > > 
> > > >     Overall result: FAILED (see details below)
> > > >              Merge: OK
> > > >            Compile: OK
> > > >              Tests: FAILED
> > > > 
> > > > All kernel binaries, config files, and logs are available for download
> > > > here:
> > > > 
> > > >   https://artifacts.cki-project.org/pipelines/262380
> > > > 
> > > > One or more kernel tests failed:
> > > > 
> > > >     x86_64:
> > > >      ❌ LTP lite
> > > >
> > > 
> > > Not a 5.3 -stable regression.
> > > 
> > > Failure comes from test that sanity checks all /proc files by doing
> > > 1k read from each. There are couple issues it hits wrt. snd_hda_*.
> > > 
> > > Example reproducer:
> > >   dd if=/sys/kernel/debug/regmap/hdaudioC0D3-hdaudio/access of=out.txt
> > >   count=1 bs=1024 iflag=nonblock
> > 
> > That's not a proc file :)
> 
> Right. It's same test that's used for /proc too.
> 
> > 
> > > It's slow and triggers soft lockups [1]. And it also requires lot
> > > of memory, triggering OOMs on smaller VMs:
> > > 0x0000000024f0437b-0x000000001a32b1c8 1073745920 seq_read+0x131/0x400
> > > pages=262144 vmalloc vpages N0=262144
> > > 
> > > I'm leaning towards skipping all regmap entries in this test.
> > > Comments are welcomed.
> > 
> > Randomly poking around in debugfs is a sure way to cause crashes and
> > major problems.  Also, debugfs files are NOT stable and only for
> > debugging and should never be enabled on "real" systems.
> > 
> > So what exactly is the test trying to do here?
> 
> It's (unprivileged) user trying to open/read anything it can (/proc, /sys)
> to see if that triggers anything bad.
> 
> It can run as privileged user too, which was the case above.

Sure, you can do tons of bad things as root poking around in sysfs,
debugfs, and procfs.  What exactly are you trying to do, break the
system?

That sounds like a horrible test that is just setting itself up to lock
the system up, you should revisit it...

thanks,

greg k-h