[PULL 4/6] linux-user: Modify 'target_to_host/host_to_target_itimerspec()'

[Laurent Vivier]

From: Filip Bozuta <Filip.Bozuta@syrmia.com>

Functions 'target_to_host_itimerspec()' and 'host_to_target_itimerspec()'
are used to convert values of type 'struct itimerspec' between target and
host. This type has 'struct timespec' as its fields. That is the reason
why this patch introduces a little modification to the converting functions
to be implemented using already existing functions that convert 'struct 
timespec':
'target_to_host_timespec()' and 'host_to_target_timespec()'. This makes the
code of 'target_to_host_itimerspec()' and 'host_to_target_itimerspec()' more
clean and readable.

Signed-off-by: Filip Bozuta <Filip.Bozuta@syrmia.com>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <20200722153421.295411-2-Filip.Bozuta@syrmia.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
---
 linux-user/syscall.c | 46 ++++++++++++++++++--------------------------
 1 file changed, 19 insertions(+), 27 deletions(-)

diff --git a/linux-user/syscall.c b/linux-user/syscall.c
index 945fc252791c..aea1160804a2 100644
--- a/linux-user/syscall.c
+++ b/linux-user/syscall.c
@@ -1229,7 +1229,9 @@ static inline abi_long copy_to_user_timeval64(abi_ulong 
target_tv_addr,
     defined(TARGET_NR_nanosleep) || defined(TARGET_NR_clock_settime) || \
     defined(TARGET_NR_utimensat) || defined(TARGET_NR_mq_timedsend) || \
     defined(TARGET_NR_mq_timedreceive) || defined(TARGET_NR_ipc) || \
-    defined(TARGET_NR_semop) || defined(TARGET_NR_semtimedop)
+    defined(TARGET_NR_semop) || defined(TARGET_NR_semtimedop) || \
+    defined(TARGET_NR_timer_settime) || \
+    (defined(TARGET_NR_timerfd_settime) && defined(CONFIG_TIMERFD))
 static inline abi_long target_to_host_timespec(struct timespec *host_ts,
                                                abi_ulong target_addr)
 {
@@ -6783,46 +6785,36 @@ static inline abi_long target_ftruncate64(void 
*cpu_env, abi_long arg1,
 
 #if defined(TARGET_NR_timer_settime) || \
     (defined(TARGET_NR_timerfd_settime) && defined(CONFIG_TIMERFD))
-static inline abi_long target_to_host_itimerspec(struct itimerspec 
*host_itspec,
+static inline abi_long target_to_host_itimerspec(struct itimerspec *host_its,
                                                  abi_ulong target_addr)
 {
-    struct target_itimerspec *target_itspec;
-
-    if (!lock_user_struct(VERIFY_READ, target_itspec, target_addr, 1)) {
+    if (target_to_host_timespec(&host_its->it_interval, target_addr +
+                                offsetof(struct target_itimerspec,
+                                         it_interval)) ||
+        target_to_host_timespec(&host_its->it_value, target_addr +
+                                offsetof(struct target_itimerspec,
+                                         it_value))) {
         return -TARGET_EFAULT;
     }
 
-    host_itspec->it_interval.tv_sec =
-                            tswapal(target_itspec->it_interval.tv_sec);
-    host_itspec->it_interval.tv_nsec =
-                            tswapal(target_itspec->it_interval.tv_nsec);
-    host_itspec->it_value.tv_sec = tswapal(target_itspec->it_value.tv_sec);
-    host_itspec->it_value.tv_nsec = tswapal(target_itspec->it_value.tv_nsec);
-
-    unlock_user_struct(target_itspec, target_addr, 1);
     return 0;
 }
 #endif
 
 #if ((defined(TARGET_NR_timerfd_gettime) || \
       defined(TARGET_NR_timerfd_settime)) && defined(CONFIG_TIMERFD)) || \
-    defined(TARGET_NR_timer_gettime) || defined(TARGET_NR_timer_settime)
+      defined(TARGET_NR_timer_gettime) || defined(TARGET_NR_timer_settime)
 static inline abi_long host_to_target_itimerspec(abi_ulong target_addr,
-                                               struct itimerspec *host_its)
-{
-    struct target_itimerspec *target_itspec;
-
-    if (!lock_user_struct(VERIFY_WRITE, target_itspec, target_addr, 0)) {
+                                                 struct itimerspec *host_its)
+{
+    if (host_to_target_timespec(target_addr + offsetof(struct 
target_itimerspec,
+                                                       it_interval),
+                                &host_its->it_interval) ||
+        host_to_target_timespec(target_addr + offsetof(struct 
target_itimerspec,
+                                                       it_value),
+                                &host_its->it_value)) {
         return -TARGET_EFAULT;
     }
-
-    target_itspec->it_interval.tv_sec = tswapal(host_its->it_interval.tv_sec);
-    target_itspec->it_interval.tv_nsec = 
tswapal(host_its->it_interval.tv_nsec);
-
-    target_itspec->it_value.tv_sec = tswapal(host_its->it_value.tv_sec);
-    target_itspec->it_value.tv_nsec = tswapal(host_its->it_value.tv_nsec);
-
-    unlock_user_struct(target_itspec, target_addr, 0);
     return 0;
 }
 #endif
-- 
2.26.2