CVS commit: [netbsd-9] src/sys/arch/xen/x86

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Tue Feb 23 11:02:12 UTC 2021

Modified Files:
        src/sys/arch/xen/x86 [netbsd-9]: xen_shm_machdep.c

Log Message:
Pull up following revision(s) (requested by jdolecek in ticket #1210):

        sys/arch/xen/x86/xen_shm_machdep.c: revision 1.17 (via patch)

in xen_shm_map(), make sure to unmap any successfully mapped pages
before returning failure if there is partial failure
fix detection of partial failure - GNTTABOP_map_grant_ref can actually re=
turn

zero for partial failure, so we need to always check all the entries
to detect it

previously, kernel triggered panic() for partial failure, leading to
Dom0 page fault later; since the mapping failure can be triggered by
malicious DomU via bad grant reference, it's important to expect
the calls to fail, and handle it gracefully without crashing Dom0

part of fixes for XSA-362


To generate a diff of this commit:
cvs rdiff -u -r1.13 -r1.13.4.1 src/sys/arch/xen/x86/xen_shm_machdep.c

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