[xen master] domain: fix misaligned unmap address in {,un}map_guest_area()

[patchbot@xxxxxxx]

commit 6ba83845924723f3b354a30f29a3ae18d713d5de
Author:     Roger Pau Monné <roger.pau@xxxxxxxxxx>
AuthorDate: Fri Oct 6 15:00:58 2023 +0200
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Fri Oct 6 18:16:31 2023 +0100

    domain: fix misaligned unmap address in {,un}map_guest_area()
    
    unmap_domain_page_global() expects the provided address to be page aligned, 
or
    else some of the called functions will trigger assertions, like
    modify_xen_mappings() on x86 or destroy_xen_mappings() on Arm.
    
    The following assert has been reported by osstest arm 32bit tests:
    
      (XEN) Assertion 'IS_ALIGNED(s, PAGE_SIZE)' failed at arch/arm/mm.c:1243
      (XEN) ----[ Xen-4.18-rc  arm32  debug=y  Not tainted ]----
      (XEN) CPU:    0
      (XEN) PC:     00271a38 destroy_xen_mappings+0x50/0x5c
      [...]
      (XEN) Xen call trace:
      (XEN)    [<00271a38>] destroy_xen_mappings+0x50/0x5c (PC)
      (XEN)    [<00235aa8>] vunmap+0x30/0x1a0 (LR)
      (XEN)    [<0026ad88>] unmap_domain_page_global+0x10/0x20
      (XEN)    [<00208e38>] unmap_guest_area+0x90/0xec
      (XEN)    [<00208f98>] domain_kill+0x104/0x180
      (XEN)    [<00239e3c>] do_domctl+0x8ac/0x14fc
      (XEN)    [<0027ae34>] do_trap_guest_sync+0x570/0x66c
      (XEN)    [<002019f0>] arch/arm/arm32/entry.o#return_from_trap+0/0x4
    
    Fixes: eadc288cbb0d ('domain: map/unmap GADDR based shared guest areas')
    Signed-off-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Release-acked-by: Henry Wang <Henry.Wang@xxxxxxx>
    Reviewed-by: Julien Grall <jgrall@xxxxxxxxxx>
---
 xen/common/domain.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/xen/common/domain.c b/xen/common/domain.c
index b8281d7cff..1468638ade 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -1601,7 +1601,7 @@ int map_guest_area(struct vcpu *v, paddr_t gaddr, 
unsigned int size,
  unmap:
     if ( pg )
     {
-        unmap_domain_page_global(map);
+        unmap_domain_page_global((void *)((unsigned long)map & PAGE_MASK));
         put_page_and_type(pg);
     }
 
@@ -1634,7 +1634,7 @@ void unmap_guest_area(struct vcpu *v, struct guest_area 
*area)
 
     if ( pg )
     {
-        unmap_domain_page_global(map);
+        unmap_domain_page_global((void *)((unsigned long)map & PAGE_MASK));
         put_page_and_type(pg);
     }
 }
--
generated by git-patchbot for /home/xen/git/xen.git#master