Re: [PATCH 18/20] arm64: ptrace: handle ptrace_request differently for aarch32 and ilp32

From: James Morse
Date: Fri Jun 23 2017 - 13:04:51 EST

Hi Yury,

On 04/06/17 13:00, Yury Norov wrote:
> ILP32 has context-related structures different from both aarch32 and
> aarch64/lp64. In this patch compat_arch_ptrace() renamed to
> compat_a32_ptrace(), and compat_arch_ptrace() only makes choice between
> compat_a32_ptrace() and new compat_ilp32_ptrace() handler.
> compat_ilp32_ptrace() calls generic compat_ptrace_request() for all
> requests except PTRACE_GETSIGMASK and PTRACE_SETSIGMASK, which need
> special handling.

Can you elaborate on this special handling?

How come we don't need to wrap PTRACE_{G,S}ETSIGMASK for aarch32 compat?
>From kernel/signal32.c that uses compat_sigset_t too.

It looks like aarch64, ilp32 and aarch32 all use the same size sigset_t,
so doesn't compat_ptrace_request() already do everything we need?


Is this fixing an endian problem? If so, can we document it as such. Do we
already have the same bug for aarch32 compat?