Re: ptrace single-stepping change breaks Wine

From: Linus Torvalds
Date: Mon Nov 22 2004 - 11:50:38 EST




On Mon, 22 Nov 2004, Andreas Schwab wrote:

> Linus Torvalds <torvalds@xxxxxxxx> 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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/