| Message ID | 20241115101225.70556-1-roger.pau@citrix.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | x86/mm: fix alignment check for non-present entries | expand |
On 15.11.2024 11:12, Roger Pau Monne wrote: > While the alignment of the mfn is not relevant for non-present entries, the > alignment of the linear address is. Commit 5b52e1b0436f introduced a > regression by not checking the alignment of the linear address when the new > entry was a non-present one. > > Fix by always checking the alignment of the linear address, non-present entries > must just skip the alignment check of the physical address. > > Fixes: 5b52e1b0436f ('x86/mm: skip super-page alignment checks for non-present entries') > Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> > Suggested-by: Jan Beulich <jbeulich@suse.com> > Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> Reviewed-by: Jan Beulich <jbeulich@suse.com>
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c index 5d7e8d78718c..494c14e80ff9 100644 --- a/xen/arch/x86/mm.c +++ b/xen/arch/x86/mm.c @@ -5525,7 +5525,7 @@ int map_pages_to_xen( ol3e = *pl3e; if ( cpu_has_page1gb && - (!(flags & _PAGE_PRESENT) || IS_L3E_ALIGNED(virt, mfn)) && + IS_L3E_ALIGNED(virt, flags & _PAGE_PRESENT ? mfn : _mfn(0)) && nr_mfns >= (1UL << (L3_PAGETABLE_SHIFT - PAGE_SHIFT)) && !(flags & (_PAGE_PAT | MAP_SMALL_PAGES)) ) { @@ -5644,7 +5644,7 @@ int map_pages_to_xen( if ( !pl2e ) goto out; - if ( (!(flags & _PAGE_PRESENT) || IS_L2E_ALIGNED(virt, mfn)) && + if ( IS_L2E_ALIGNED(virt, flags & _PAGE_PRESENT ? mfn : _mfn(0)) && (nr_mfns >= (1u << PAGETABLE_ORDER)) && !(flags & (_PAGE_PAT|MAP_SMALL_PAGES)) ) {
While the alignment of the mfn is not relevant for non-present entries, the alignment of the linear address is. Commit 5b52e1b0436f introduced a regression by not checking the alignment of the linear address when the new entry was a non-present one. Fix by always checking the alignment of the linear address, non-present entries must just skip the alignment check of the physical address. Fixes: 5b52e1b0436f ('x86/mm: skip super-page alignment checks for non-present entries') Reported-by: Andrew Cooper <andrew.cooper3@citrix.com> Suggested-by: Jan Beulich <jbeulich@suse.com> Signed-off-by: Roger Pau Monné <roger.pau@citrix.com> --- xen/arch/x86/mm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)