usermem: fix error handling

diff --git a/Kernel/usermem.c b/Kernel/usermem.c
index 0cbec96..fae355d 100644 (file)
--- a/Kernel/usermem.c
+++ b/Kernel/usermem.c
@@ -13,7 +13,7 @@ usize_t valaddr(const char *base, usize_t size)
 {
        if (base < (const char *)PROGBASE || base + size < base)
                size = 0;
-       if (base + size > (const char *)udata.u_top)
+       else if (base + size > (const char *)udata.u_top)
                size = (char *)udata.u_top - base;
        if (size == 0)
                udata.u_error = EFAULT;