1 files changed, 14 insertions, 39 deletions

diff --git a/kernel/compat.c b/kernel/compat.c
index 32c254a8ab9a..72650e39b3e6 100644
--- a/kernel/compat.c
+++ b/kernel/compat.c
@@ -23,6 +23,7 @@
 #include <linux/timex.h>
 #include <linux/migrate.h>
 #include <linux/posix-timers.h>
+#include <linux/times.h>
 
 #include <asm/uaccess.h>
 
@@ -150,49 +151,23 @@ asmlinkage long compat_sys_setitimer(int which,
         return 0;
 }
 
+static compat_clock_t clock_t_to_compat_clock_t(clock_t x)
+{
+        return compat_jiffies_to_clock_t(clock_t_to_jiffies(x));
+}
+
 asmlinkage long compat_sys_times(struct compat_tms __user *tbuf)
 {
-        /*
-         *      In the SMP world we might just be unlucky and have one of
-         *      the times increment as we use it. Since the value is an
-         *      atomically safe type this is just fine. Conceptually its
-         *      as if the syscall took an instant longer to occur.
-         */
         if (tbuf) {
+                struct tms tms;
                 struct compat_tms tmp;
-                struct task_struct *tsk = current;
-                struct task_struct *t;
-                cputime_t utime, stime, cutime, cstime;
-
-                read_lock(&tasklist_lock);
-                utime = tsk->signal->utime;
-                stime = tsk->signal->stime;
-                t = tsk;
-                do {
-                        utime = cputime_add(utime, t->utime);
-                        stime = cputime_add(stime, t->stime);
-                        t = next_thread(t);
-                } while (t != tsk);
-
-                /*
-                 * While we have tasklist_lock read-locked, no dying thread
-                 * can be updating current->signal->[us]time.  Instead,
-                 * we got their counts included in the live thread loop.
-                 * However, another thread can come in right now and
-                 * do a wait call that updates current->signal->c[us]time.
-                 * To make sure we always see that pair updated atomically,
-                 * we take the siglock around fetching them.
-                 */
-                spin_lock_irq(&tsk->sighand->siglock);
-                cutime = tsk->signal->cutime;
-                cstime = tsk->signal->cstime;
-                spin_unlock_irq(&tsk->sighand->siglock);
-                read_unlock(&tasklist_lock);
-
-                tmp.tms_utime = compat_jiffies_to_clock_t(cputime_to_jiffies(utime));
-                tmp.tms_stime = compat_jiffies_to_clock_t(cputime_to_jiffies(stime));
-                tmp.tms_cutime = compat_jiffies_to_clock_t(cputime_to_jiffies(cutime));
-                tmp.tms_cstime = compat_jiffies_to_clock_t(cputime_to_jiffies(cstime));
+
+                do_sys_times(&tms);
+                /* Convert our struct tms to the compat version. */
+                tmp.tms_utime = clock_t_to_compat_clock_t(tms.tms_utime);
+                tmp.tms_stime = clock_t_to_compat_clock_t(tms.tms_stime);
+                tmp.tms_cutime = clock_t_to_compat_clock_t(tms.tms_cutime);
+                tmp.tms_cstime = clock_t_to_compat_clock_t(tms.tms_cstime);
                 if (copy_to_user(tbuf, &tmp, sizeof(tmp)))
                         return -EFAULT;
         }