Re: [PATCH]: Fix thread debugging on Sparc/Linux

["David S. Miller" <davem@davemloft.net>]

From: Daniel Jacobowitz <drow@false.org>
Date: Tue, 4 Apr 2006 18:43:41 -0400

> In that case, I can save you one bit of debugging: a lot of thread
> tests are broken on SPARC, because linux_nat_thread_alive (or something
> with a similar name) tries to use PTRACE_PEEKUSR to test whether a
> thread is alive, but the SPARC ptrace interface doesn't implement that,
> only PTRACE_GETREGS.

I'm two shoelaces ahead of you.

I'm adding support for PTRACE_PEEKUSER with offset 0 in the kernel in
order to cure this.  Linux/Sparc is the only platform that doesn't
support this and just returning a dummy zero value for this special
case is fine with me.

There are many more much deeper issues once you get past this, which
I plan to get to.  I need reliable Linux thread debugging in gdb in
order to work on Mono.

The checkpoint/restart stuff is also non-functional on Linux/Sparc,
but I think that could be due to some bug in event message handling on
that platform.