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

Jan Stancek
2019-11-04T14:28:10Z

----- 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.

[1] https://github.com/linux-test-project/ltp/blob/master/testcases/kernel/fs/read_all/read_all.c