Re: [PATCH 1/3] x86_64, entry: Remove a bogus ret_from_fork optimization

From: Ingo Molnar
Date: Wed Feb 25 2015 - 02:23:37 EST



* Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote:

> ret_from_fork checks TIF_IA32 to determine whether pt_regs and the
> related state make sense for ret_from_sys_call. This is entirely
> the wrong check. TS_COMPAT would make a little more sense, but
> there's really no point in keeping this optimization at all.
>
> This fixes a return to the wrong user CS if we came from int 0x80 in
> a 64-bit task.
>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>

Acked-by: Ingo Molnar <mingo@xxxxxxxxxx>

Thanks,

Ingo
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