Re: ptrace && fpu_lazy_restore

From: Oleg Nesterov
Date: Sat Apr 14 2012 - 20:00:48 EST


forgot to mention just in case...

On 04/15, Oleg Nesterov wrote:
>
> --- x/arch/x86/kernel/i387.c~ 2012-04-09 20:12:12.000000000 +0200
> +++ x/arch/x86/kernel/i387.c 2012-04-15 01:34:09.000000000 +0200
> @@ -301,6 +301,8 @@ int xfpregs_set(struct task_struct *targ
>
> sanitize_i387_state(target);
>
> + target->thread.fpu.last_cpu = ~0;
> +
> ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
> &target->thread.fpu.state->fxsave, 0, -1);
>
> @@ -563,6 +565,8 @@ int fpregs_set(struct task_struct *targe
>
> sanitize_i387_state(target);
>
> + target->thread.fpu.last_cpu = ~0;
> +
> if (!HAVE_HWFP)
> return fpregs_soft_set(target, regset, pos, count, kbuf, ubuf);
>

with this hack the test-case works fine.

Oleg.

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