f11 X "hang"

Adam Jackson ajax at redhat.com
Tue Jun 2 17:33:07 UTC 2009


On Tue, 2009-06-02 at 07:36 -0700, David L wrote:

> Would it be possible for strace to detect that you're tracing
> an X app based on the system calls you're making?  I guess
> that would add more overhead to something that already slows down
> the traced app.  If the app was dynamically linked, maybe it could
> just check for libX* library dependencies?

System calls... nngh.  Library calls would be easier, though it would
involve porting a fair chunk of ltrace into strace.

> What about the other way around... can an app check
> if it's being straced before doing a server grab?  Do server grabs
> happen so frequently that the overhead of checking for stracing
> would be unacceptable?

Server grabs aren't that frequent, certainly not enough to be a
performance concern, but detecting that you're under a debugger is
non-trivial.

The biggest problem with trying to detect this scenario is that there
are cases where it's perfectly legit.  For example, if I ssh into
another box and strace an X app running (and displaying) there, that's
fine, because the strace output is interacting with a different X
server.

- ajax
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 197 bytes
Desc: This is a digitally signed message part
URL: <http://listman.redhat.com/archives/fedora-test-list/attachments/20090602/d2d47118/attachment.sig>


More information about the fedora-test-list mailing list