[xen staging] x86/pv: Deduplicate is_canonical_address() in do_set_segment_base()

[patchbot@xxxxxxx]

commit 524f3fa35efd7a425e1033d2fa5c927f61224d67
Author:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
AuthorDate: Tue Aug 12 12:48:06 2025 +0100
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Fri Dec 5 23:00:32 2025 +0000

    x86/pv: Deduplicate is_canonical_address() in do_set_segment_base()
    
    This is really a rearrangement to make adding FRED support easier.
    
    No functional change.
    
    Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
    Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
 xen/arch/x86/pv/misc-hypercalls.c | 32 +++++++++++++++++---------------
 1 file changed, 17 insertions(+), 15 deletions(-)

diff --git a/xen/arch/x86/pv/misc-hypercalls.c 
b/xen/arch/x86/pv/misc-hypercalls.c
index 7a37f16bf0..4c2abeb4ad 100644
--- a/xen/arch/x86/pv/misc-hypercalls.c
+++ b/xen/arch/x86/pv/misc-hypercalls.c
@@ -176,27 +176,29 @@ long do_set_segment_base(unsigned int which, unsigned 
long base)
     switch ( which )
     {
     case SEGBASE_FS:
-        if ( is_canonical_address(base) )
-            write_fs_base(base);
-        else
+    case SEGBASE_GS_USER:
+    case SEGBASE_GS_KERNEL:
+        if ( !is_canonical_address(base) )
+        {
             ret = -EINVAL;
-        break;
+            break;
+        }
 
-    case SEGBASE_GS_USER:
-        if ( is_canonical_address(base) )
+        switch ( which )
         {
-            write_gs_shadow(base);
+        case SEGBASE_FS:
+            write_fs_base(base);
+            break;
+
+        case SEGBASE_GS_USER:
             v->arch.pv.gs_base_user = base;
-        }
-        else
-            ret = -EINVAL;
-        break;
+            write_gs_shadow(base);
+            break;
 
-    case SEGBASE_GS_KERNEL:
-        if ( is_canonical_address(base) )
+        case SEGBASE_GS_KERNEL:
             write_gs_base(base);
-        else
-            ret = -EINVAL;
+            break;
+        }
         break;
 
     case SEGBASE_GS_USER_SEL:
--
generated by git-patchbot for /home/xen/git/xen.git#staging