Fix iovec for the case with invalid elements (Lauro Ramos Venancio).

We must call the writev even if an iovec element is invalid. For
example, if the second element is invalid, the linux process the first
one.

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5562 c046a42c-6fe2-441c-8c8c-71466251a162

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 91deb80..06d1597 100644 (file)
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -1064,7 +1064,7 @@ static abi_long lock_iovec(int type, struct iovec *vec, abi_ulong target_addr,
 {
     struct target_iovec *target_vec;
     abi_ulong base;
-    int i, j;
+    int i;
 
     target_vec = lock_user(VERIFY_READ, target_addr, count * sizeof(struct target_iovec), 1);
     if (!target_vec)
@@ -1074,8 +1074,8 @@ static abi_long lock_iovec(int type, struct iovec *vec, abi_ulong target_addr,
         vec[i].iov_len = tswapl(target_vec[i].iov_len);
         if (vec[i].iov_len != 0) {
             vec[i].iov_base = lock_user(type, base, vec[i].iov_len, copy);
-            if (!vec[i].iov_base && vec[i].iov_len) 
-                goto fail;
+            /* Don't check lock_user return value. We must call writev even
+               if a element has invalid base address. */
         } else {
             /* zero length pointer is ignored */
             vec[i].iov_base = NULL;
@@ -1083,14 +1083,6 @@ static abi_long lock_iovec(int type, struct iovec *vec, abi_ulong target_addr,
     }
     unlock_user (target_vec, target_addr, 0);
     return 0;
- fail:
-    /* failure - unwind locks */
-    for (j = 0; j < i; j++) {
-        base = tswapl(target_vec[j].iov_base);
-        unlock_user(vec[j].iov_base, base, 0);
-    }
-    unlock_user (target_vec, target_addr, 0);
-    return -TARGET_EFAULT;
 }
 
 static abi_long unlock_iovec(struct iovec *vec, abi_ulong target_addr,
@@ -1104,8 +1096,10 @@ static abi_long unlock_iovec(struct iovec *vec, abi_ulong target_addr,
     if (!target_vec)
         return -TARGET_EFAULT;
     for(i = 0;i < count; i++) {
-        base = tswapl(target_vec[i].iov_base);
-        unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
+        if (target_vec[i].iov_base) {
+            base = tswapl(target_vec[i].iov_base);
+            unlock_user(vec[i].iov_base, base, copy ? vec[i].iov_len : 0);
+        }
     }
     unlock_user (target_vec, target_addr, 0);