Re: [PATCH 1/1] mm: sysctl: add panic_on_inconsistent_mm sysctl

[Kees Cook]

On Thu, Jan 30, 2020 at 03:44:50PM +0100, Vlastimil Babka wrote:
> On 1/29/20 7:08 PM, Grzegorz Halat wrote:
> > Memory management subsystem performs various checks at runtime,
> > if an inconsistency is detected then such event is being logged and kernel
> > continues to run. While debugging such problems it is helpful to collect
> > memory dump as early as possible. Currently, there is no easy way to panic
> > kernel when such error is detected.
> > 
> > It was proposed[1] to panic the kernel if panic_on_oops is set but this
> > approach was not accepted. One of alternative proposals was introduction of
> > a new sysctl.
> > 
> > Add a new sysctl - panic_on_inconsistent_mm. If the sysctl is set then the
> > kernel will be crashed when an inconsistency is detected by memory
> > management. This currently means panic when bad page or bad PTE
> > is detected(this may be extended to other places in MM).
> 
> I wonder, should enabling the sysctl also effectively convert VM_WARN...
> to VM_BUG... ?

There is already panic_on_warn sysctl... wouldn't that be sufficient?

-- 
Kees Cook