Re: Kernel oops with 2.6.26, padlock and ipsec: probably problem with fpu state changes

Herbert Xu
2008-08-10T01:41:08Z

On Sat, Aug 09, 2008 at 10:59:40AM -0700, Suresh Siddha wrote:
>
> 0. CPU's TS flag is set
>
> 1. kernel using FPU in some optimized copy routine and while doing
> kernel_fpu_begin() takes an interrupt just before doing clts()
>
> 2. Takes an interrupt and ipsec uses padlock instruction. And we
> take a DNA fault as TS flag is still set.

Right, we could've fixed this by doing the clts before checking
TS_USEDFPU in kernel_fpu_begin. However, I admit that taking a
fault in the general case for the PadLock is stupid anyway so we
should definitely fix this in the ways that you suggested.

Cheers,
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