Re: [PATCH v5 06/27] x86/cet: Control protection exception handler

Yu-cheng Yu
2018-11-14T20:19:42Z

On Wed, 2018-11-14 at 19:44 +0100, Borislav Petkov wrote:
> That subject needs a verb:
>
> Subject: [PATCH v5 06/27] x86/cet: Add control protection exception handler
>
> On Thu, Oct 11, 2018 at 08:15:02AM -0700, Yu-cheng Yu wrote:
> > A control protection exception is triggered when a control flow transfer
> > attempt violated shadow stack or indirect branch tracking constraints.
> > For example, the return address for a RET instruction differs from the
> > safe copy on the shadow stack; or a JMP instruction arrives at a non-
> > ENDBR instruction.
> >
> > The control protection exception handler works in a similar way as the
> > general protection fault handler.
> >
> > Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
> > ---
> > arch/x86/entry/entry_64.S | 2 +-
> > arch/x86/include/asm/traps.h | 3 ++
> > arch/x86/kernel/idt.c | 4 ++
> > arch/x86/kernel/signal_compat.c | 2 +-
> > arch/x86/kernel/traps.c | 64 ++++++++++++++++++++++++++++++
> > include/uapi/asm-generic/siginfo.h | 3 +-
> > 6 files changed, 75 insertions(+), 3 deletions(-)
>
> A *lot* of style problems here. Please use checkpatch and then common
> sense to check your patches before sending. All those below are valid,
> AFAICT:
>
> WARNING: function definition argument 'struct pt_regs *' should also have an
> identifier name
> #76: FILE: arch/x86/include/asm/traps.h:81:
> +dotraplinkage void do_control_protection(struct pt_regs *, long);
>
> WARNING: function definition argument 'long' should also have an identifier
> name
> #76: FILE: arch/x86/include/asm/traps.h:81:
> +dotraplinkage void do_control_protection(struct pt_regs *, long);

Yes, I was not sure if the addition should follow the existing style (which does
not have identifier names). What do you think is right?

Thanks,
Yu-cheng