Messages in this thread | | | Date | Sat, 04 Nov 2006 11:19:53 -0800 | From | Zachary Amsden <> | Subject | Re: [patch] i386: remove IOPL check on task switch |
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Chuck Ebbert wrote: > In-Reply-To: <454B850C.3050402@vmware.com> > > On Fri, 03 Nov 2006 10:06:04 -0800, Zachary Amsden wrote: > > >> Chuck Ebbert wrote: >> >>> IOPL is implicitly saved and restored on task switch, >>> so explicit check is no longer needed. >>> >> Nack. This is used for paravirt-ops kernels that use IOPL'd userspace. >> > > How does that work? In the stock kernel, anything done by > the call to set_iopl_mask() (that was removed by the patch) > will be nullified by the 'popfl' at the end of the switch_to() > macro. >
Who put a popfl back in switch_to? I took it out some time ago. It should not be there. The only reason for it was to stop IOPL leaking from one process to another from a sleep during a sysenter based system call.
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