CVS commit: src/sys/arch/hppa/hppa

[Nick Hudson <skrll%netbsd.org@localhost>]

Module Name:    src
Committed By:   skrll
Date:           Fri Apr  2 15:25:51 UTC 2010

Modified Files:
        src/sys/arch/hppa/hppa: pmap.c

Log Message:
Pull across pmap_remove fix from OpenBSD.

Fix user-after-free bug in pmap_remove().  Page table pages are freed as soon
as the last page table entry that was actually used is cleared.  So make sure
we check the page table page is still there for every page we remove.
Otherwise we will bring back the tlb entry and cache lines when we touch the
freed page, and we will create an illegal alias (non-equivalent mapping)
as soon as the page gets re-used.


To generate a diff of this commit:
cvs rdiff -u -r1.74 -r1.75 src/sys/arch/hppa/hppa/pmap.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.