Messages in this thread | | | Date | Fri, 14 Sep 2018 13:05:10 +0200 (CEST) | From | Thomas Gleixner <> | Subject | RE: [PATCH v6 1/3] x86/speculation: apply IBPB more strictly to avoid cross-process data leak |
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On Fri, 14 Sep 2018, Jiri Kosina wrote: > On Thu, 13 Sep 2018, Schaufler, Casey wrote: > > > > - return security_ptrace_access_check(task, mode); > > > + if (!(mode & PTRACE_MODE_NOACCESS_CHK)) > > > + return security_ptrace_access_check(task, mode); > > > + return 0; > > > > Because PTRACE_MODE_IBPB includes PTRACE_MODE_NOAUDIT you > > shouldn't need this change. > > That is true, but that's not my concern here. > > security_ptrace_access_check() -> call_int_hook() -> P->hook.FUNC(). > > If it's somehow guaranteed that all functions called this ways are fine to > be called from scheduler context (wrt. locks), then it's all fine and I'll > happily drop that check. > > Is it guaranteed?
The related question is whether it is guaranteed for backports. We don't want to end up with a separate hell there.
Thanks,
tglx
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