On Wed, 29 Dec 2004, Jesse Allen wrote:
So does removing the conditional TF clear make everything work again?
Yes, as long as TIF_SINGLESTEP is not set in set_singlestep().
That may be a clue, if only because that makes absolutely _zero_ sense.
Setting TIF_SINGLESTEP shouldn't actually matter in this case, since we set the TRAP_FLAG in eflags by hand anyway (and that's what TIF_SINGESTEP will just re-do when returning to user space).
What TIF_SINGLESTEP _does_ do, however, is change how some other issues are reported to user space. In particular, it causes system call tracing (see arch/i386/kernel/ptrace.c: do_syscall_trace), and maybe it is _that_ that messes up Wine.
So instead of removing the setting of TIF_SINGLESTEP in set_singlestep(), can you test whether removing the _testing_ of it in do_syscall_trace() makes things happier for you? Hmm?
(Also, looking at the code, I get the feeling that set_singlestep() should _only_ set TIF_SINGLESTEP, and not set the TRAP_FLAG by hand at all, since TIF_SINGESTEP should take care of that detail regardless).
Linus