[PATCH 01/16] move copyout of timespec into do_cpu_nanosleep()

[Al Viro]

From: Al Viro <v...@zeniv.linux.org.uk>

Signed-off-by: Al Viro <v...@zeniv.linux.org.uk>
---
 kernel/time/posix-cpu-timers.c | 62 ++++++++++++++++++------------------------
 1 file changed, 27 insertions(+), 35 deletions(-)

diff --git a/kernel/time/posix-cpu-timers.c b/kernel/time/posix-cpu-timers.c
index cb4a4eb44279..ef1f2bdc896e 100644
--- a/kernel/time/posix-cpu-timers.c
+++ b/kernel/time/posix-cpu-timers.c
@@ -1226,9 +1226,10 @@ void set_process_cpu_timer(struct task_struct *tsk, 
unsigned int clock_idx,
 }
 
 static int do_cpu_nanosleep(const clockid_t which_clock, int flags,
-                           struct timespec64 *rqtp, struct itimerspec64 *it)
+                           struct timespec64 *rqtp)
 {
        struct k_itimer timer;
+       struct itimerspec64 it;
        int error;
 
        /*
@@ -1242,12 +1243,14 @@ static int do_cpu_nanosleep(const clockid_t 
which_clock, int flags,
        timer.it_process = current;
        if (!error) {
                static struct itimerspec64 zero_it;
+               struct restart_block *restart = &current->restart_block;
+               struct timespec __user *rmtp;
 
-               memset(it, 0, sizeof *it);
-               it->it_value = *rqtp;
+               memset(&it, 0, sizeof it);
+               it.it_value = *rqtp;
 
                spin_lock_irq(&timer.it_lock);
-               error = posix_cpu_timer_set(&timer, flags, it, NULL);
+               error = posix_cpu_timer_set(&timer, flags, &it, NULL);
                if (error) {
                        spin_unlock_irq(&timer.it_lock);
                        return error;
@@ -1277,7 +1280,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, 
int flags,
                 * We were interrupted by a signal.
                 */
                *rqtp = ns_to_timespec64(timer.it.cpu.expires);
-               error = posix_cpu_timer_set(&timer, 0, &zero_it, it);
+               error = posix_cpu_timer_set(&timer, 0, &zero_it, &it);
                if (!error) {
                        /*
                         * Timer is now unarmed, deletion can not fail.
@@ -1297,7 +1300,7 @@ static int do_cpu_nanosleep(const clockid_t which_clock, 
int flags,
                        spin_unlock_irq(&timer.it_lock);
                }
 
-               if ((it->it_value.tv_sec | it->it_value.tv_nsec) == 0) {
+               if ((it.it_value.tv_sec | it.it_value.tv_nsec) == 0) {
                        /*
                         * It actually did fire already.
                         */
@@ -1305,6 +1308,17 @@ static int do_cpu_nanosleep(const clockid_t which_clock, 
int flags,
                }
 
                error = -ERESTART_RESTARTBLOCK;
+               /*
+                * Report back to the user the time still remaining.
+                */
+               rmtp = restart->nanosleep.rmtp;
+               if (rmtp) {
+                       struct timespec ts;
+                       ts = timespec64_to_timespec(it.it_value);
+                       if (copy_to_user(rmtp, &ts, sizeof(*rmtp)))
+                               return -EFAULT;
+               }
+               restart->nanosleep.expires = timespec64_to_ns(rqtp);
        }
 
        return error;
@@ -1316,10 +1330,13 @@ static int posix_cpu_nsleep(const clockid_t 
which_clock, int flags,
                            struct timespec64 *rqtp, struct timespec __user 
*rmtp)
 {
        struct restart_block *restart_block = &current->restart_block;
-       struct itimerspec64 it;
-       struct timespec ts;
        int error;
 
+       if (flags & TIMER_ABSTIME)
+               rmtp = NULL;
+
+       restart_block->nanosleep.rmtp = rmtp;
+
        /*
         * Diagnose required errors first.
         */
@@ -1328,23 +1345,15 @@ static int posix_cpu_nsleep(const clockid_t 
which_clock, int flags,
             CPUCLOCK_PID(which_clock) == task_pid_vnr(current)))
                return -EINVAL;
 
-       error = do_cpu_nanosleep(which_clock, flags, rqtp, &it);
+       error = do_cpu_nanosleep(which_clock, flags, rqtp);
 
        if (error == -ERESTART_RESTARTBLOCK) {
 
                if (flags & TIMER_ABSTIME)
                        return -ERESTARTNOHAND;
-               /*
-                * Report back to the user the time still remaining.
-                */
-               ts = timespec64_to_timespec(it.it_value);
-               if (rmtp && copy_to_user(rmtp, &ts, sizeof(*rmtp)))
-                       return -EFAULT;
 
                restart_block->fn = posix_cpu_nsleep_restart;
                restart_block->nanosleep.clockid = which_clock;
-               restart_block->nanosleep.rmtp = rmtp;
-               restart_block->nanosleep.expires = timespec64_to_ns(rqtp);
        }
        return error;
 }
@@ -1352,28 +1361,11 @@ static int posix_cpu_nsleep(const clockid_t 
which_clock, int flags,
 static long posix_cpu_nsleep_restart(struct restart_block *restart_block)
 {
        clockid_t which_clock = restart_block->nanosleep.clockid;
-       struct itimerspec64 it;
        struct timespec64 t;
-       struct timespec tmp;
-       int error;
 
        t = ns_to_timespec64(restart_block->nanosleep.expires);
 
-       error = do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t, &it);
-
-       if (error == -ERESTART_RESTARTBLOCK) {
-               struct timespec __user *rmtp = restart_block->nanosleep.rmtp;
-               /*
-                * Report back to the user the time still remaining.
-                */
-                tmp = timespec64_to_timespec(it.it_value);
-               if (rmtp && copy_to_user(rmtp, &tmp, sizeof(*rmtp)))
-                       return -EFAULT;
-
-               restart_block->nanosleep.expires = timespec64_to_ns(&t);
-       }
-       return error;
-
+       return do_cpu_nanosleep(which_clock, TIMER_ABSTIME, &t);
 }
 
 #define PROCESS_CLOCK  MAKE_PROCESS_CPUCLOCK(0, CPUCLOCK_SCHED)
-- 
2.11.0