* Roland McGrath <rol...@redhat.com> wrote:
> Here is a trivial module to implement the seccomp guts via utrace.
> I haven't tested it at all. (AFAIK it was only ever used by
> cpushare, and that project might be defunct now.)
>
> I'm not sure what Ingo had in mind for integrating this. If it's
> just to reimplement the existing prctl interface, then this is
> about all you need--just s/_xxx// and fiddle the config et al to
> build this and not the old stuff.
>
> If the approach would be incremental, to leave the old stuff in
> place, then it might make more sense just to do a fresh new thing
> not providing that prctl interface at all. A new thing could be a
> module, and define some /sys files or whatnot for its "constrain
> me now" hook. I think a sensible thing would not require
> asm/seccomp.h at all, and instead just let the userland setup feed
> in a set of syscall numbers. It could be that flexible while still
> being quite simple so that one could audit that setup code and be
> confident it has no holes. Then future versions of cpushare (or
> whatever) would not need any special kernel support for new arch's
> nor to change the syscall set it wants to allow.
nice! The simplification factor is already significant:
18 files changed, 116 insertions(+), 175 deletions(-)
That is what we want - to remove special TIF flag uses and replace
them with utrace driven machinery.
Another future target could be to replace TIF_SYSCALL_FTRACE [in the
latest tracing tree] with a similar utrace driven solution.
Regarding ptrace-via-utrace. What is the plan there? Am i looking
the right branch:
| earth4:~/linux.trees.git> git diff --stat
| linus/master..utrace/utrace-ptrace kernel/ptrace.c arch/x86/kernel/ptrace.c
| kernel/ptrace.c | 803
++++++++++++++++++++++++++++++++++++++++++++++++++++++-
| 1 files changed, 794 insertions(+), 9 deletions(-)
dc43527: Merge branch 'utrace' into utrace-ptrace
I'd have (perhaps foolishly) expected ptrace.c to get reduced in
size and arch/x86/kernel/ptrace.c eliminated - but that does not
seem to be direction of movement. What am i missing?
Ingo
