port-i386/38289: a possible problem in x86 pmap_update

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>Number:         38289
>Category:       port-i386
>Synopsis:       a possible problem in x86 pmap_update
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    port-i386-maintainer
>State:          open
>Class:          sw-bug
>Submitter-Id:   net
>Arrival-Date:   Mon Mar 24 09:10:00 +0000 2008
>Originator:     YAMAMOTO Takashi <yamt%mwd.biglobe.ne.jp@localhost>
>Release:        NetBSD 4.99.57
>Organization:
        
>Environment:
Architecture: i386
Machine: i386
>Description:
        x86 pmap_update assumes that it's called on the same cpu on which
        pmap_kenter_pa etc is called.  however,
        - there are code which can sleep before calling pmap_update.
          eg. uvm_km_alloc
        - it isn't safe with (future) in-kernel preemption.
>How-To-Repeat:
        code inspection.
>Fix:
        do the pmap_update equivalent when switching lwps?

>Unformatted: