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.


Thanks,
Roland
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