[Valgrind-developers] Any recent changes in ptrace handling on ppc32/64 kernels?

[Julian S. <js...@ac...>]

Paul

Valgrind has an mechanism whereby it can attach GDB to the client
process, so users can poke around when an error occurs to see what's
going on.  It works using fork/ptrace.  See coregrind/m_debugger.c.

Recently said mechanism stopped working on amd64-linux.  Turned out to
be that the kernel's sanity checking for ptrace(PTRACE_SETREGS, ...) 
was tightened up around 2.6.20/21, causing the failure.  Easily fixed.
See http://bugs.kde.org/show_bug.cgi?id=145622

Now I've been trying to get same functionality implemented for ppc64-linux
(it never has been so far).
See http://bugs.kde.org/show_bug.cgi?id=151908
After some futzing around it appears that
the mechanism works for ppc32-linux and ppc64-linux for kernel 2.6.20
but fails in some bizarre way on 2.6.23.  

So now I'm wondering if ptrace handling on ppc platforms has also
been made more paranoid, or otherwise changed, lately?  Do you know?

Thanks,

J