[v6,19/31] linux-user: Handle tags in lock_user/unlock_user

Commit Message

Richard Henderson Feb. 10, 2021, 12:02 a.m. UTC

Resolve the untagged address once, using thread_cpu.
Tidy the DEBUG_REMAP code using glib routines.

Signed-off-by: Richard Henderson <[e-mail]>
---
 linux-user/uaccess.c | 27 ++++++++++++++-------------
 1 file changed, 14 insertions(+), 13 deletions(-)

Comments

Peter Maydell Feb. 10, 2021, 11:05 a.m. UTC | #1

On Wed, 10 Feb 2021 at 00:02, Richard Henderson
<[e-mail]> wrote:
>
> Resolve the untagged address once, using thread_cpu.
> Tidy the DEBUG_REMAP code using glib routines.
>
> Signed-off-by: Richard Henderson <[e-mail]>
> ---
>  linux-user/uaccess.c | 27 ++++++++++++++-------------

Reviewed-by: Peter Maydell <[e-mail]>

thanks
-- PMM

Patch

diff --git a/linux-user/uaccess.c b/linux-user/uaccess.c
index 76af6a92b1..c696913016 100644
--- a/linux-user/uaccess.c
+++ b/linux-user/uaccess.c
@@ -6,36 +6,37 @@ 
 
 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
-    {
-        void *addr;
-        addr = g_malloc(len);
-        if (copy) {
-            memcpy(addr, g2h(guest_addr), len);
-        } else {
-            memset(addr, 0, len);
-        }
-        return addr;
+    if (copy) {
+        host_addr = g_memdup(host_addr, len);
+    } else {
+        host_addr = g_malloc0(len);
     }
-#else
-    return g2h_untagged(guest_addr);
 #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;
     }
-    if (host_ptr == g2h_untagged(guest_addr)) {
+    host_ptr_conv = g2h(thread_cpu, guest_addr);
+    if (host_ptr == host_ptr_conv) {
         return;
     }
     if (len != 0) {
-        memcpy(g2h_untagged(guest_addr), host_ptr, len);
+        memcpy(host_ptr_conv, host_ptr, len);
     }
     g_free(host_ptr);
 }