Re: [PATCH][DEBUG] x86/refcount: split up refcount saturation handling

[Ingo Molnar]

* Kees Cook <keescook@xxxxxxxxxxxx> wrote:

> In support of debugging the problems Mike Galbraith has seen with
> x86-refcount vs gcc vs network refcounts...
> 
> This minimizes the differences between unchecked-refcount and x86-refcount
> by changing the refcount_dec() failure case to not saturate. The reporting
> of negative values is reduced to pr_warn from WARN to avoid spamming dmesg
> (which may impact race conditions). Ratelimiting is disabled just to be
> sure no reports are being dropped.
> 
> Signed-off-by: Kees Cook <keescook@xxxxxxxxxxxx>
> ---
>  arch/x86/mm/extable.c | 51 ++++++++++++++++++++++++++++++++++-----------------
>  kernel/panic.c        |  2 +-
>  2 files changed, 35 insertions(+), 18 deletions(-)

If this patch is still useful then please include it in your next refcount series. 
Better debuggability is always welcome.

Thanks,

	Ingo