Re: ptrace single-stepping change breaks Wine

Eric Pouech
2004-11-19T20:41:47Z

> Btw, does wine ever _use_ PTRACE_SINGLESTEP for any of the things it does?
>
> If it does, then that woulc certainly explain why my "fix" made no
> difference: my fix _only_ handles the case where the ptracer never
> actually asks for single-stepping, and single-stepping was started
> entirely by the program being run (ie by setting TF in eflags from within
> the program itself).
>
> But if wine ends up using PTRACE_SINGESTEP because wine actually wants to
> single-step over some instructions, then the kernel will set the PT_DTRACE
> bit, and start tracing through signal handlers too. The way Wine doesn't
> want..

wine mixes both approches, we have (to control what's generated inside the
various exception) to ptrace from our NT-kernel-like process (the ptracer) to
get the context of the exception. Restart from the ptracer is done with
PTRACE_SINGLESTEP.

(BTW: I also CC:ed wine-devel ML, that might be of interest to them too)

A+