Re: [PATCH seccomp 3/8] powerpc: Enable seccomp architecture tracking

[YiFei Zhu]

On Wed, Nov 4, 2020 at 4:22 AM Michael Ellerman <mpe@xxxxxxxxxxxxxx> wrote:
> > +#ifdef __LITTLE_ENDIAN__
>
> As Kees mentioned this should (must?!) match the configured endian.
>
> But I think it would still be better to use the CONFIG symbol, which is
> CONFIG_CPU_LITTLE_ENDIAN.

My attempt here is to be consistent with asm/syscall.h
syscall_get_arch [1]. Would it make sense to change that to
CONFIG_CPU_LITTLE_ENDIAN then?

[1] https://elixir.bootlin.com/linux/latest/source/arch/powerpc/include/asm/syscall.h#L116

> > +# define SECCOMP_ARCH_NATIVE         (AUDIT_ARCH_PPC64 | __SECCOMP_ARCH_LE)
>
> You use __SECCOMP_ARCH_LE there, but previously you only defined
> __SECCOMP_ARCH_LE_BIT.
>
> Is there some magic somewhere that defines __SECCOMP_ARCH_LE based on
> __SECCOMP_ARCH_LE_BIT ?

Oops, my bad here.

> > +# define SECCOMP_ARCH_NATIVE_NR              NR_syscalls
> > +# define SECCOMP_ARCH_NATIVE_NAME    "ppc64"
>
> What's the name used for?

This is used in the last patch in this series to report in procfs the
name of each architecture tracked by the bitmap cache.

> Usually we use "ppc64" for 64-bit big endian and "ppc64le" for 64-bit
> little endian.
>
> And usually we use "ppc" for 32-bit.

Ok.

YiFei Zhu