[PATCH] arm: ptrace: fix syscall modification under PTRACE_O_TRACESECCOMP

Will Deacon will.deacon at arm.com
Tue Jun 24 01:54:05 PDT 2014


On Mon, Jun 23, 2014 at 08:46:52PM +0100, Kees Cook wrote:
> On Mon, Jun 23, 2014 at 1:46 AM, Will Deacon <will.deacon at arm.com> wrote:
> > On Fri, Jun 20, 2014 at 07:10:46PM +0100, Kees Cook wrote:
> >> On Fri, Jun 20, 2014 at 10:36 AM, Kees Cook <keescook at chromium.org> wrote:
> >> > On Fri, Jun 20, 2014 at 10:23 AM, Will Deacon <will.deacon at arm.com> wrote:
> >> >> Right, gotcha. Thanks for the explanation. I was confused, because
> >> >> tracehook_report_syscall does the right thing (returns
> >> >> current_thread_info()->syscall), but if we don't have TIF_SYSCALL_TRACE set,
> >> >> then updates during the secure_computing callback will be ignored.
> >> >>
> >> >> However, my fix to this is significantly smaller than your patch, so I fear
> >> >> I'm still missing something.
> >> >
> >> > Oh, yes, that's much smaller. Nice! I will test this and report back.
> >>
> >> Yup, I can confirm this works. Thanks!
> >>
> >> Tested-by: Kees Cook <keescook at chromium.org>
> >
> > Thanks, Kees. I'll post a patch shortly. I'll try and remember to keep an
> > eye out for this when seccomp lands for arm64 too.
> 
> Great, thanks!
> 
> What's the state of seccomp on arm64? I saw a series back in March,
> but nothing since then? It looked complete, but I haven't set up a
> test environment yet to verify.

I think Akashi was going to repost `real soon now' so we can include them
for 3.17. He missed the merge window last time around.

Will



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