[xen master] x86/mem-paging: fold p2m_mem_paging_prep()'s main if()-s

[patchbot@xxxxxxx]

commit c2612852288c410846e41a7a882317e8bc55b9ff
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri May 15 15:57:56 2020 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri May 15 15:57:56 2020 +0200

    x86/mem-paging: fold p2m_mem_paging_prep()'s main if()-s
    
    The condition of the second can be true only if the condition of the
    first was met; the second half of the condition of the second then also
    is redundant with an earlier check. Combine them, drop a pointless
    local variable, and take the liberty to drop the affected gdprintk()
    altogether, as we don't normally log anything on -EFAULT paths.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
    Acked-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
---
 xen/arch/x86/mm/p2m.c | 16 ++++------------
 1 file changed, 4 insertions(+), 12 deletions(-)

diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 4c1507d3a4..92c5ca6d37 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -1808,6 +1808,8 @@ int p2m_mem_paging_prep(struct domain *d, unsigned long 
gfn_l, uint64_t buffer)
     /* Allocate a page if the gfn does not have one yet */
     if ( !mfn_valid(mfn) )
     {
+        void *guest_map;
+
         /* If the user did not provide a buffer, we disallow */
         ret = -EINVAL;
         if ( unlikely(user_ptr == NULL) )
@@ -1819,22 +1821,12 @@ int p2m_mem_paging_prep(struct domain *d, unsigned long 
gfn_l, uint64_t buffer)
             goto out;
         mfn = page_to_mfn(page);
         page_extant = 0;
-    }
-
-    /* If we were given a buffer, now is the time to use it */
-    if ( !page_extant && user_ptr )
-    {
-        void *guest_map;
-        int rc;
 
-        ASSERT( mfn_valid(mfn) );
         guest_map = map_domain_page(mfn);
-        rc = copy_from_user(guest_map, user_ptr, PAGE_SIZE);
+        ret = copy_from_user(guest_map, user_ptr, PAGE_SIZE);
         unmap_domain_page(guest_map);
-        if ( rc )
+        if ( ret )
         {
-            gdprintk(XENLOG_ERR, "Failed to load paging-in gfn %lx domain %u "
-                                 "bytes left %d\n", gfn_l, d->domain_id, rc);
             ret = -EFAULT;
             put_page(page); /* Don't leak pages */
             goto out;            
--
generated by git-patchbot for /home/xen/git/xen.git#master