[PULL 73/87] migration: check length directly to make sure the range is aligned

[Paolo Bonzini]

From: Wei Yang <address@hidden>

Since the start addr is already checked, to make sure the range is
aligned, checking the length is enough.

Signed-off-by: Wei Yang <address@hidden>
Reviewed-by: Dr. David Alan Gilbert <address@hidden>
Message-Id: <address@hidden>
Signed-off-by: Paolo Bonzini <address@hidden>
---
 exec.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/exec.c b/exec.c
index a34c348..dfe2096 100644
--- a/exec.c
+++ b/exec.c
@@ -3901,10 +3901,9 @@ int ram_block_discard_range(RAMBlock *rb, uint64_t 
start, size_t length)
 
     if ((start + length) <= rb->used_length) {
         bool need_madvise, need_fallocate;
-        uint8_t *host_endaddr = host_startaddr + length;
-        if ((uintptr_t)host_endaddr & (rb->page_size - 1)) {
-            error_report("ram_block_discard_range: Unaligned end address: %p",
-                         host_endaddr);
+        if (length & (rb->page_size - 1)) {
+            error_report("ram_block_discard_range: Unaligned length: %zx",
+                         length);
             goto err;
         }
 
-- 
1.8.3.1