diff mbox series

[v2,4/4] x86/mm: ensure L2 is always freed if empty

Message ID 20241106122927.26461-5-roger.pau@citrix.com (mailing list archive)
State Superseded
Headers show
Series x86/mm: miscellaneous fixes | expand

Commit Message

Roger Pau Monné Nov. 6, 2024, 12:29 p.m. UTC 
The current logic in modify_xen_mappings() allows for fully empty L2 tables to
not be freed and unhooked from the parent L3 if the last L2 slot is not
populated.

Ensure that even when an L2 slot is empty the logic to check whether the whole
L2 can be removed is not skipped.

Fixes: 4376c05c3113 ('x86-64: use 1GB pages in 1:1 mapping if available')
Signed-off-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
---
 xen/arch/x86/mm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 8f7c397a82d4..05d3ba095627 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -5712,7 +5712,7 @@  int modify_xen_mappings(unsigned long s, unsigned long e, unsigned int nf)
 
             v += 1UL << L2_PAGETABLE_SHIFT;
             v &= ~((1UL << L2_PAGETABLE_SHIFT) - 1);
-            continue;
+            goto check_l3;
         }
 
         if ( l2e_get_flags(*pl2e) & _PAGE_PSE )