Re: [PATCH 11/18] kprobes: disable kretprobes with SCS

Masami Hiramatsu
2019-10-21T09:19:38Z

On Fri, 18 Oct 2019 13:04:29 -0400
Steven Rostedt <rostedt@goodmis.org> wrote:

>
> [ Added Masami ]
>
> On Fri, 18 Oct 2019 09:10:26 -0700
> Sami Tolvanen <samitolvanen@google.com> wrote:
>
> > With CONFIG_KRETPROBES, function return addresses are modified to
> > redirect control flow to kretprobe_trampoline. This is incompatible with
> > return address protection.
> >
> > Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
> > ---
> > arch/Kconfig | 2 +-
> > 1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/arch/Kconfig b/arch/Kconfig
> > index a222adda8130..4646e3b34925 100644
> > --- a/arch/Kconfig
> > +++ b/arch/Kconfig
> > @@ -171,7 +171,7 @@ config ARCH_USE_BUILTIN_BSWAP
> >
> > config KRETPROBES
> > def_bool y
> > - depends on KPROBES && HAVE_KRETPROBES
> > + depends on KPROBES && HAVE_KRETPROBES && ROP_PROTECTION_NONE
>
> Again, this belongs in the arch code.

+1, below patch (from Steve) looks good to me.

Thank you,

>
> -- Steve
>
> >
> > config USER_RETURN_NOTIFIER
> > bool
>
>
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 41a9b4257b72..65557d7e6b5e 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -166,7 +166,7 @@ config ARM64
> select HAVE_STACKPROTECTOR
> select HAVE_SYSCALL_TRACEPOINTS
> select HAVE_KPROBES
> - select HAVE_KRETPROBES
> + select HAVE_KRETPROBES if ROP_PROTECTION_NONE
> select HAVE_GENERIC_VDSO
> select IOMMU_DMA if IOMMU_SUPPORT
> select IRQ_DOMAIN

--
Masami Hiramatsu <mhiramat@kernel.org>