lkml.org 
[lkml]   [2018]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH v4] powerpc/ptrace: replace ptrace_report_syscall() with a tracehook call
On Fri, Dec 07, 2018 at 05:34:10PM +0100, Oleg Nesterov wrote:
> On 12/07, Dmitry V. Levin wrote:
> > On Fri, Dec 07, 2018 at 10:12:49PM +1100, Michael Ellerman wrote:
> >
> > > > Sorry, this patch does not work, please ignore it.
> > >
> > > Hmm OK. Why exactly?
> >
> > Unfortunately, I have no idea why it doesn't work.
> > All I can say is it breaks strace because the kernel no longer sends
> > syscall entry stops.
>
> May be because TIF_SYSCALL_EMU/etc is a bit number, not a mask? IOW, rather
> than
>
> whatever & TIF_XXX
>
> you should do
>
> whatever & _TIF_XXX
>
> intstead?

Thanks Oleg, this was exactly the reason why it didn't work.
That kind of things happens when you let userspace people hack you kernel. :)


--
ldv
[unhandled content-type:application/pgp-signature]
\
 
 \ /
  Last update: 2018-12-07 19:43    [W:0.102 / U:7.528 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site