linux-user: fix timerfd read endianness conversion

When reading the expiration count from a timerfd, the endianness of the
64bit value read is the one of the host, just as for eventfds.

Signed-off-by: Mathis Marion <mathis.marion@silabs.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20230220085822.626798-2-Mathis.Marion@silabs.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

linux-user/fd-trans.c

@@ -1622,7 +1622,7 @@ TargetFdTrans target_signalfd_trans = {
     .host_to_target_data = host_to_target_data_signalfd,
 };
 
-static abi_long swap_data_eventfd(void *buf, size_t len)
+static abi_long swap_data_u64(void *buf, size_t len)
 {
     uint64_t *counter = buf;
     int i;
@@ -1640,8 +1640,12 @@ static abi_long swap_data_eventfd(void *buf, size_t len)
 }
 
 TargetFdTrans target_eventfd_trans = {
-    .host_to_target_data = swap_data_eventfd,
-    .target_to_host_data = swap_data_eventfd,
+    .host_to_target_data = swap_data_u64,
+    .target_to_host_data = swap_data_u64,
+};
+
+TargetFdTrans target_timerfd_trans = {
+    .host_to_target_data = swap_data_u64,
 };
 
 #if defined(CONFIG_INOTIFY) && (defined(TARGET_NR_inotify_init) || \

linux-user/fd-trans.h

@@ -130,6 +130,7 @@ extern TargetFdTrans target_netlink_route_trans;
 extern TargetFdTrans target_netlink_audit_trans;
 extern TargetFdTrans target_signalfd_trans;
 extern TargetFdTrans target_eventfd_trans;
+extern TargetFdTrans target_timerfd_trans;
 #if (defined(TARGET_NR_inotify_init) && defined(__NR_inotify_init)) || \
     (defined(CONFIG_INOTIFY1) && defined(TARGET_NR_inotify_init1) && \
      defined(__NR_inotify_init1))

linux-user/syscall.c

@@ -13108,8 +13108,12 @@ static abi_long do_syscall1(CPUArchState *cpu_env, int num, abi_long arg1,
 
 #if defined(TARGET_NR_timerfd_create) && defined(CONFIG_TIMERFD)
     case TARGET_NR_timerfd_create:
-        return get_errno(timerfd_create(arg1,
-                          target_to_host_bitmask(arg2, fcntl_flags_tbl)));
+        ret = get_errno(timerfd_create(arg1,
+                        target_to_host_bitmask(arg2, fcntl_flags_tbl)));
+        if (ret >= 0) {
+            fd_trans_register(ret, &target_timerfd_trans);
+        }
+        return ret;
 #endif
 
 #if defined(TARGET_NR_timerfd_gettime) && defined(CONFIG_TIMERFD)