Re: [PATCH 5.10 00/21] 5.10.81-rc1 review

[Greg Kroah-Hartman]

On Sat, Nov 20, 2021 at 09:36:55PM +0530, Naresh Kamboju wrote:
> + Peter Zijlstra
> + Thomas Gleixner
> + Borislav Petkov
> + Ondrej Zary
> 
> 
> On Sat, 20 Nov 2021 at 20:57, Daniel Díaz <daniel.diaz@xxxxxxxxxx> wrote:
> >
> > Hello!
> >
> > On 11/19/21 11:37 AM, Greg Kroah-Hartman wrote:
> > > This is the start of the stable review cycle for the 5.10.81 release.
> > > There are 21 patches in this series, all will be posted as a response
> > > to this one.  If anyone has any issues with these being applied, please
> > > let me know.
> > >
> > > Responses should be made by Sun, 21 Nov 2021 17:14:35 +0000.
> > > Anything received after that time might be too late.
> > >
> > > The whole patch series can be found in one patch at:
> > >       https://www.kernel.org/pub/linux/kernel/v5.x/stable-review/patch-5.10.81-rc1.gz
> > > or in the git tree and branch at:
> > >       git://git.kernel.org/pub/scm/linux/kernel/git/stable/linux-stable-rc.git linux-5.10.y
> > > and the diffstat can be found below.
> > >
> > > thanks,
> > >
> > > greg k-h
> > >
> > > -------------
> > > Pseudo-Shortlog of commits:
> > >
> > > Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> > >      Linux 5.10.81-rc1
> > [...]> Peter Zijlstra <peterz@xxxxxxxxxxxxx>
> > >      x86/iopl: Fake iopl(3) CLI/STI usage
> 
> This is due to  ^ new kernel code + old test case (Test case needs to
> be updated)
> 
> > [...]
> >
> > Results from Linaro's test farm.
> > Regressions found on x86_64 and i386, on iopl. Here's an excerpt of the selftest:
> >
> >    [    0.000000] Linux version 5.10.81-rc1 (oe-user@oe-host) (x86_64-linaro-linux-gcc (GCC) 7.3.0, GNU ld (GNU Binutils) 2.30.0.20180208) #1 SMP Fri Nov 19 19:48:55 UTC 2021
> > [...]
> >    [  170.351838] traps: iopl_64[2769] attempts to use CLI/STI, pretending it's a NOP, ip:400dde in iopl_64[400000+2000]
> > [...]
> >    # selftests: x86: iopl_64
> >    # [FAIL]     CLI worked
> >    # [FAIL]     STI worked
> 
> This failure was detected on linux next and the later test case has been fixed.
> The Following patch could fix this problem across 5.10, 5.14 and 5.15.
> 
> Patch details,
> ---
> selftests/x86/iopl: Adjust to the faked iopl CLI/STI usage
> 
> Commit in Fixes changed the iopl emulation to not #GP on CLI and STI
> because it would break some insane luserspace tools which would toggle
> interrupts.
> 
> The corresponding selftest would rely on the fact that executing CLI/STI
> would trigger a #GP and thus detect it this way but since that #GP is
> not happening anymore, the detection is now wrong too.
> 
> Extend the test to actually look at the IF flag and whether executing
> those insns had any effect on it. The STI detection needs to have the
> fact that interrupts were previously disabled, passed in so do that from
> the previous CLI test, i.e., STI test needs to follow a previous CLI one
> for it to make sense.
> 
> Fixes: b968e84b509d ("x86/iopl: Fake iopl(3) CLI/STI usage")
> Suggested-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Signed-off-by: Borislav Petkov <bp@xxxxxxx>
> Acked-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Link: https://lore.kernel.org/r/20211030083939.13073-1-bp@xxxxxxxxx

Now queued up, thanks,

greg k-h