Re: [REGRESSION] 5.16rc1: SA_IMMUTABLE breaks debuggers

From: Kees Cook
Date: Fri Nov 19 2021 - 11:36:03 EST

On Fri, Nov 19, 2021 at 08:07:36AM -0800, Kyle Huey wrote:
> On Thu, Nov 18, 2021 at 8:12 AM Eric W. Biederman <ebiederm@xxxxxxxxxxxx> wrote:
> > Kyle thank you for your explanation of what breaks. For future kernels
> > I do need to do some work in this area and I will copy on the patches
> > going forward. In particular I strongly suspect that changing the
> > sigaction and blocked state of the signal for these synchronous signals
> > is the wrong thing to do, especially if the process is not killed. I
> > want to find another solution that does not break things but that also
> > does not change the program state behind the programs back so things
> > work differently under the debugger.
> The heads up in the future is appreciated, thanks.

Yeah, I wonder if we could add you as a Reviewer in the MAINTAINERS file
for ptrace/signal stuff? Then anyone using scripts/
would have a CC to you added.

Also, are there more instructions about running the rr tests? When the
execve refactoring was happening, I tried it[1], but the results were
unclear (there seemed to be a lot of warnings and it made me think I'd
done something wrong on my end).



Kees Cook