[Linux-kernel-mentees] [STABLE TEST] 5.3.13

[Greg KH]

On Tue, Dec 03, 2019 at 12:44:15PM +0530, Amol Grover wrote:
> On Tue, Dec 03, 2019 at 07:40:52AM +0100, Greg KH wrote:
> > On Tue, Dec 03, 2019 at 11:55:03AM +0530, Amol Grover wrote:
> > > Compiled, Booted, however I'm getting the following errors when running
> > > "make kselftest"
> > > 
> > > sudo dmesg -l alert
> > > 
> > > [34381.903893] BUG: kernel NULL pointer dereference, address: 0000000000000008
> > > [34381.903904] #PF: supervisor read access in kernel mode
> > > [34381.903908] #PF: error_code(0x0000) - not-present page
> > 
> > Which test causes this problem?
> 
> IIRC I didn't run make kselftest with summary=1 option. Is there any
> other way to get that information? The logs that kselftest generated
> also don't seem to help in this.

Watch the output when you run this?  I don't know, try re-running it
with that option.

> > ANd is it new in 5.3.13?
> > 
> 
> I previously ran kselftest on 5.4-rc7 and 5.3.9 (default kernel shipped
> by openSUSE), both were fine. However, a bit of backstory:
> 
> A day ago I used kselftest from the linux/next branch and ran it (w/o
> sudo).  It showed me the exact same error. However, I was running a
> modified version of 5.3.13, but those modifications were actually
> trivial (5 lines changed) and shouldn't have resulted in this kernel
> error. So, I switched to the vanilla 5.3.13 and ran kselftest (w/o sudo)
> again. I ran it 3 times (w/o any errors), switched back to the modified
> kernel and ran kselftest (w/o root) 2 more times and everything was
> fine. Then I decided to test the vanilla one again for the 4th time, but
> this time I ran kselftest as root where this BUG popped again.

Try a kernel.org 5.3.9 and if that works, then try 5.3.13 and if that
fails, run 'git bisect' and try to find the offending kernel commit.

thanks,

greg k-h