[PATCH v2 Zisslpcfi 0/2] Support for zisslpcfi in opensbi

[Anup Patel]

On Thu, Dec 22, 2022 at 5:09 AM Deepak Gupta <debug at rivosinc.com> wrote:
>
> Please don't bother with your time and ignore this patch series.
> Something went wrong on my setup and patches didn't come out as expected.
>
> I'll send a new version.

Okay, we will wait for another version.

Regards,
Anup

> Apologies.
>
> -Deepak
>
> On Wed, Dec 21, 2022 at 11:55 AM Deepak Gupta <debug at rivosinc.com> wrote:
> >
> > Zisslpcfi [1] extension extends risc-v architecture to mitigate against
> > control-flow integrity attacks (ROP/JOP/COP).
> >
> > Zisslpcfi uses bits (b23-b29) in (m/s/vs) status CSR for enabling cfi in
> > lesser privileged mode and record cfi state. One such state is expected
> > landing pad (ELP). If forward cfi is enabled, indirect call/jmp updates
> > hart's ELP state (1bit) to true. ELP state is cleared only by a landing
> > pad instruction else trap is delivered with ELP state recorded in sstatus
> > CSR.
> >
> > This two patch series adds following changes to opensbi
> >     - Adds support in opensbi to detect zisslpcfi
> >     - trap redirection updates ELP state accordingly
> >
> > Qemu implementation for Zisslpcfi can be checked out on github [2]
> > Strawman linux kernel enabling (still very early) can be checked out on github [3]
> >
> > [1] - https://github.com/riscv/riscv-cfi
> > [2] - https://github.com/deepak0414/qemu/tree/gh_Zisslpcfi-0.1
> > [3] - https://github.com/deepak0414/linux-riscv-cfi/tree/Zisslpcfi-0.1_v6.1-rc2
> >
> > Deepak Gupta (2):
> >   include: adding support for Zisslpcfi encodings
> >   lib: sbi: Zisslpcfi detection and elp cfi state reflect back in status
> >
> >  include/sbi/riscv_encoding.h |  6 ++++++
> >  include/sbi/sbi_hart.h       |  2 ++
> >  lib/sbi/sbi_hart.c           | 21 +++++++++++++++++++++
> >  lib/sbi/sbi_trap.c           | 18 ++++++++++++++++++
> >  4 files changed, 47 insertions(+)
> >
> > --
> > 2.25.1
> >
>
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