Author: kib Date: Wed Jul 4 21:21:59 2018 New Revision: 335969 URL: https://svnweb.freebsd.org/changeset/base/335969
Log: In x86 pmap_extract_and_hold()s, handle the case of PHYS_TO_VM_PAGE() returning NULL. vm_fault_quick_hold_pages() can be legitimately called on userspace mappings backed by fictitious pages created by unmanaged device and sg pagers. Note that other architectures pmap_extract_and_hold() might need similar fix, but I postponed the examination. Reported by: bde Discussed with: alc Reviewed by: markj Sponsored by: The FreeBSD Foundation MFC after: 2 weeks Differential revision: https://reviews.freebsd.org/D16085 Modified: head/sys/amd64/amd64/pmap.c head/sys/i386/i386/pmap.c Modified: head/sys/amd64/amd64/pmap.c ============================================================================== --- head/sys/amd64/amd64/pmap.c Wed Jul 4 19:46:26 2018 (r335968) +++ head/sys/amd64/amd64/pmap.c Wed Jul 4 21:21:59 2018 (r335969) @@ -2319,7 +2319,8 @@ retry: &pa)) goto retry; m = PHYS_TO_VM_PAGE(pte & PG_FRAME); - vm_page_hold(m); + if (m != NULL) + vm_page_hold(m); } } } Modified: head/sys/i386/i386/pmap.c ============================================================================== --- head/sys/i386/i386/pmap.c Wed Jul 4 19:46:26 2018 (r335968) +++ head/sys/i386/i386/pmap.c Wed Jul 4 21:21:59 2018 (r335969) @@ -1684,7 +1684,8 @@ retry: &pa)) goto retry; m = PHYS_TO_VM_PAGE(pte & PG_FRAME); - vm_page_hold(m); + if (m != NULL) + vm_page_hold(m); } } } _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
