1 files changed, 65 insertions, 17 deletions

diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c
index e215ecc2a6..c696913016 100644
--- a/linux-user/uaccess.c
+++ b/linux-user/uaccess.c
@@ -4,46 +4,93 @@
 
 #include "qemu.h"
 
+void *lock_user(int type, abi_ulong guest_addr, size_t len, bool copy)
+{
+    void *host_addr;
+
+    guest_addr = cpu_untagged_addr(thread_cpu, guest_addr);
+    if (!access_ok_untagged(type, guest_addr, len)) {
+        return NULL;
+    }
+    host_addr = g2h_untagged(guest_addr);
+#ifdef DEBUG_REMAP
+    if (copy) {
+        host_addr = g_memdup(host_addr, len);
+    } else {
+        host_addr = g_malloc0(len);
+    }
+#endif
+    return host_addr;
+}
+
+#ifdef DEBUG_REMAP
+void unlock_user(void *host_ptr, abi_ulong guest_addr, size_t len);
+{
+    void *host_ptr_conv;
+
+    if (!host_ptr) {
+        return;
+    }
+    host_ptr_conv = g2h(thread_cpu, guest_addr);
+    if (host_ptr == host_ptr_conv) {
+        return;
+    }
+    if (len != 0) {
+        memcpy(host_ptr_conv, host_ptr, len);
+    }
+    g_free(host_ptr);
+}
+#endif
+
+void *lock_user_string(abi_ulong guest_addr)
+{
+    ssize_t len = target_strlen(guest_addr);
+    if (len < 0) {
+        return NULL;
+    }
+    return lock_user(VERIFY_READ, guest_addr, (size_t)len + 1, 1);
+}
+
 /* copy_from_user() and copy_to_user() are usually used to copy data
  * buffers between the target and host.  These internally perform
  * locking/unlocking of the memory.
  */
-abi_long copy_from_user(void *hptr, abi_ulong gaddr, size_t len)
+int copy_from_user(void *hptr, abi_ulong gaddr, size_t len)
 {
-    abi_long ret = 0;
-    void *ghptr;
+    int ret = 0;
+    void *ghptr = lock_user(VERIFY_READ, gaddr, len, 1);
 
-    if ((ghptr = lock_user(VERIFY_READ, gaddr, len, 1))) {
+    if (ghptr) {
         memcpy(hptr, ghptr, len);
         unlock_user(ghptr, gaddr, 0);
-    } else
+    } else {
         ret = -TARGET_EFAULT;
-
+    }
     return ret;
 }
 
-
-abi_long copy_to_user(abi_ulong gaddr, void *hptr, size_t len)
+int copy_to_user(abi_ulong gaddr, void *hptr, size_t len)
 {
-    abi_long ret = 0;
-    void *ghptr;
+    int ret = 0;
+    void *ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0);
 
-    if ((ghptr = lock_user(VERIFY_WRITE, gaddr, len, 0))) {
+    if (ghptr) {
         memcpy(ghptr, hptr, len);
         unlock_user(ghptr, gaddr, len);
-    } else
+    } else {
         ret = -TARGET_EFAULT;
+    }
 
     return ret;
 }
 
 /* Return the length of a string in target memory or -TARGET_EFAULT if
    access error  */
-abi_long target_strlen(abi_ulong guest_addr1)
+ssize_t target_strlen(abi_ulong guest_addr1)
 {
     uint8_t *ptr;
     abi_ulong guest_addr;
-    int max_len, len;
+    size_t max_len, len;
 
     guest_addr = guest_addr1;
     for(;;) {
@@ -55,11 +102,12 @@ abi_long target_strlen(abi_ulong guest_addr1)
         unlock_user(ptr, guest_addr, 0);
         guest_addr += len;
         /* we don't allow wrapping or integer overflow */
-        if (guest_addr == 0 || 
-            (guest_addr - guest_addr1) > 0x7fffffff)
+        if (guest_addr == 0 || (guest_addr - guest_addr1) > 0x7fffffff) {
             return -TARGET_EFAULT;
-        if (len != max_len)
+        }
+        if (len != max_len) {
             break;
+        }
     }
     return guest_addr - guest_addr1;
 }