Re: [PATCH] ptrace: copy_thread() should clear TIF_SINGLESTEP andX86_EFLAGS_TF

From: Roland McGrath
Date: Fri Nov 06 2009 - 17:10:46 EST

> I thought this flag has no effect without TIF_SINGLESTEP, and it is
> always updated by enable_single_step().

Right, but to be anal about the semantics you shouldn't clear TF if it's
not set, etc.

> user_disable_single_step() is very much arch-dependent, I am worried
> if it is safe to call it from copy_process(), when the new task_struct,
> thread_info, etc are not properly initialized yet...

Well, arch people can weigh in about if it is problematical.
Skimming over the existing arch definitions, it looks OK to me.

To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at