Messages in this thread | | | Date | Fri, 12 Apr 2019 19:27:30 +0200 | From | Sebastian Andrzej Siewior <> | Subject | Re: [PATCH 24/27] x86/fpu: Add a fastpath to __fpu__restore_sig() |
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On 2019-04-12 19:17:59 [+0200], Borislav Petkov wrote: > > @@ -327,7 +327,19 @@ static int __fpu__restore_sig(void __user *buf, void __user *buf_fx, int size) > > if (ret) > > goto err_out; > > envp = &env; > > + } else { > > I've added here:
I would suggest to add it in the last patch once we have the complete fast path. The other one extended (in case you want to add a comment there, too).
> + /* /**
> + * Attempt to restore the FPU registers directly from user > + * memory. For that to succeed, the user accesses cannot cause
I would say "user access" because it is always a single instruction.
> + * page faults. If they do, fall back to the slow path below, > + * going through the kernel buffer.
"with the enabled page fault handler".
> + */ > > so that it is clear what's happening. > > This function is doing gazillion things again ;-\
It is the old code with disabled page fault handler. But I understand.
Sebastian
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