ptrace single-stepping change breaks Wine

[Linus Torvalds]

On Mon, 22 Nov 2004, Andreas Schwab wrote:

> Linus Torvalds <torvalds at osdl.org> writes:
> 
> > IMHO, this is a nice cleanup, and it also means that I can actually debug 
> > my "program from hell":
> 
> Does it also work when trying to single step over it?  I guess all bets
> are off then.

If you single-step over the "popfl", then you need to generate the
SIGTRAP's by hand too. IOW, it's _possible_ to emulate the behaviour from
within the debugger, but it gets really really nasty very quickly.

I think the nastyness in that case is at least acceptable, since if you 
single-step, you actually _see_ what is happening, and thus you have a 
chance in hell of figuring it out. Practical? No. But debuggable at least 
in theory, which it really wasn't before.

		Linus