Subject: [RESEND PATCH 2/3] fs: poll/select/recvmmsg: use timespec64 for timeout events

From: Deepa Dinamani <[email-masked]>
Date: Wed, 4 May 2016 12:24:59 -0700

struct timespec is not y2038 safe.
Even though timespec might be sufficient to represent
timeouts, use struct timespec64 here as the plan is to
get rid of all timespec reference in the kernel.

The patch transitions the common functions:
poll_select_set_timeout() and select_estimate_accuracy()
to use timespec64. And, all the syscalls that use these
functions are transitioned in the same patch.

The restart block parameters for poll uses monotonic time.
Use timespec64 here as well to assign timeout value. This
parameter in the restart block need not change because
this only holds the monotonic timestamp at which timeout
should occur. And, unsigned long data type should be big
enough for this timestamp.

The system call interfaces will be handled in a separate
series.

Compat interfaces need not change as timespec64 is an
alias to struct timespec on a 64 bit system.

Signed-off-by: Deepa Dinamani <[email-masked]>
Cc: Alexander Viro <[email-masked]>
Cc: "David S. Miller" <[email-masked]>
Cc: [email-masked]
---
Resending to include John and Thomas on this patch as well.
This is to include this patch also in John's tree.
This will let all 3 patches in the series to merged through the same tree.
 
 fs/eventpoll.c       | 12 +++++-----
 fs/select.c          | 67 +++++++++++++++++++++++++++++-----------------------
 include/linux/poll.h | 11 +++++----
 net/socket.c         |  8 ++++---
 4 files changed, 54 insertions(+), 44 deletions(-)

diff --git a/fs/eventpoll.c b/fs/eventpoll.c
index 8a74a2a..10db912 100644
--- a/fs/eventpoll.c
+++ b/fs/eventpoll.c
@@ -1583,15 +1583,15 @@ static int ep_send_events(struct eventpoll *ep,
 	return ep_scan_ready_list(ep, ep_send_events_proc, &esed, 0, false);
 }
 
-static inline struct timespec ep_set_mstimeout(long ms)
+static inline struct timespec64 ep_set_mstimeout(long ms)
 {
-	struct timespec now, ts = {
+	struct timespec64 now, ts = {
 		.tv_sec = ms / MSEC_PER_SEC,
 		.tv_nsec = NSEC_PER_MSEC * (ms % MSEC_PER_SEC),
 	};
 
-	ktime_get_ts(&now);
-	return timespec_add_safe(now, ts);
+	ktime_get_ts64(&now);
+	return timespec64_add_safe(now, ts);
 }
 
 /**
@@ -1621,11 +1621,11 @@ static int ep_poll(struct eventpoll *ep, struct epoll_event __user *events,
 	ktime_t expires, *to = NULL;
 
 	if (timeout > 0) {
-		struct timespec end_time = ep_set_mstimeout(timeout);
+		struct timespec64 end_time = ep_set_mstimeout(timeout);
 
 		slack = select_estimate_accuracy(&end_time);
 		to = &expires;
-		*to = timespec_to_ktime(end_time);
+		*to = timespec64_to_ktime(end_time);
 	} else if (timeout == 0) {
 		/*
 		 * Avoid the unnecessary trip to the wait queue loop, if the
diff --git a/fs/select.c b/fs/select.c
index 8692939..8ed9da5 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -47,7 +47,7 @@
 
 #define MAX_SLACK	(100 * NSEC_PER_MSEC)
 
-static long __estimate_accuracy(struct timespec *tv)
+static long __estimate_accuracy(struct timespec64 *tv)
 {
 	long slack;
 	int divfactor = 1000;
@@ -70,10 +70,10 @@ static long __estimate_accuracy(struct timespec *tv)
 	return slack;
 }
 
-u64 select_estimate_accuracy(struct timespec *tv)
+u64 select_estimate_accuracy(struct timespec64 *tv)
 {
 	u64 ret;
-	struct timespec now;
+	struct timespec64 now;
 
 	/*
 	 * Realtime tasks get a slack of 0 for obvious reasons.
@@ -82,8 +82,8 @@ u64 select_estimate_accuracy(struct timespec *tv)
 	if (rt_task(current))
 		return 0;
 
-	ktime_get_ts(&now);
-	now = timespec_sub(*tv, now);
+	ktime_get_ts64(&now);
+	now = timespec64_sub(*tv, now);
 	ret = __estimate_accuracy(&now);
 	if (ret < current->timer_slack_ns)
 		return current->timer_slack_ns;
@@ -260,7 +260,7 @@ EXPORT_SYMBOL(poll_schedule_timeout);
 
 /**
  * poll_select_set_timeout - helper function to setup the timeout value
- * @to:		pointer to timespec variable for the final timeout
+ * @to:		pointer to timespec64 variable for the final timeout
  * @sec:	seconds (from user space)
  * @nsec:	nanoseconds (from user space)
  *
@@ -269,26 +269,28 @@ EXPORT_SYMBOL(poll_schedule_timeout);
  *
  * Returns -EINVAL if sec/nsec are not normalized. Otherwise 0.
  */
-int poll_select_set_timeout(struct timespec *to, long sec, long nsec)
+int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec)
 {
-	struct timespec ts = {.tv_sec = sec, .tv_nsec = nsec};
+	struct timespec64 ts = {.tv_sec = sec, .tv_nsec = nsec};
 
-	if (!timespec_valid(&ts))
+	if (!timespec64_valid(&ts))
 		return -EINVAL;
 
 	/* Optimize for the zero timeout value here */
 	if (!sec && !nsec) {
 		to->tv_sec = to->tv_nsec = 0;
 	} else {
-		ktime_get_ts(to);
-		*to = timespec_add_safe(*to, ts);
+		ktime_get_ts64(to);
+		*to = timespec64_add_safe(*to, ts);
 	}
 	return 0;
 }
 
-static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
+static int poll_select_copy_remaining(struct timespec64 *end_time,
+				      void __user *p,
 				      int timeval, int ret)
 {
+	struct timespec64 rts64;
 	struct timespec rts;
 	struct timeval rtv;
 
@@ -302,16 +304,18 @@ static int poll_select_copy_remaining(struct timespec *end_time, void __user *p,
 	if (!end_time->tv_sec && !end_time->tv_nsec)
 		return ret;
 
-	ktime_get_ts(&rts);
-	rts = timespec_sub(*end_time, rts);
-	if (rts.tv_sec < 0)
-		rts.tv_sec = rts.tv_nsec = 0;
+	ktime_get_ts64(&rts64);
+	rts64 = timespec64_sub(*end_time, rts64);
+	if (rts64.tv_sec < 0)
+		rts64.tv_sec = rts64.tv_nsec = 0;
+
+	rts = timespec64_to_timespec(rts64);
 
 	if (timeval) {
 		if (sizeof(rtv) > sizeof(rtv.tv_sec) + sizeof(rtv.tv_usec))
 			memset(&rtv, 0, sizeof(rtv));
-		rtv.tv_sec = rts.tv_sec;
-		rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
+		rtv.tv_sec = rts64.tv_sec;
+		rtv.tv_usec = rts64.tv_nsec / NSEC_PER_USEC;
 
 		if (!copy_to_user(p, &rtv, sizeof(rtv)))
 			return ret;
@@ -396,7 +400,7 @@ static inline void wait_key_set(poll_table *wait, unsigned long in,
 		wait->_key |= POLLOUT_SET;
 }
 
-int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
+int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time)
 {
 	ktime_t expire, *to = NULL;
 	struct poll_wqueues table;
@@ -522,7 +526,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
 		 * pointer to the expiry value.
 		 */
 		if (end_time && !to) {
-			expire = timespec_to_ktime(*end_time);
+			expire = timespec64_to_ktime(*end_time);
 			to = &expire;
 		}
 
@@ -545,7 +549,7 @@ int do_select(int n, fd_set_bits *fds, struct timespec *end_time)
  * I'm trying ERESTARTNOHAND which restart only when you want to.
  */
 int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
-			   fd_set __user *exp, struct timespec *end_time)
+			   fd_set __user *exp, struct timespec64 *end_time)
 {
 	fd_set_bits fds;
 	void *bits;
@@ -622,7 +626,7 @@ out_nofds:
 SYSCALL_DEFINE5(select, int, n, fd_set __user *, inp, fd_set __user *, outp,
 		fd_set __user *, exp, struct timeval __user *, tvp)
 {
-	struct timespec end_time, *to = NULL;
+	struct timespec64 end_time, *to = NULL;
 	struct timeval tv;
 	int ret;
 
@@ -648,15 +652,17 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp,
 		       const sigset_t __user *sigmask, size_t sigsetsize)
 {
 	sigset_t ksigmask, sigsaved;
-	struct timespec ts, end_time, *to = NULL;
+	struct timespec ts;
+	struct timespec64 ts64, end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
 		if (copy_from_user(&ts, tsp, sizeof(ts)))
 			return -EFAULT;
+		ts64 = timespec_to_timespec64(ts);
 
 		to = &end_time;
-		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
+		if (poll_select_set_timeout(to, ts64.tv_sec, ts64.tv_nsec))
 			return -EINVAL;
 	}
 
@@ -779,7 +785,7 @@ static inline unsigned int do_pollfd(struct pollfd *pollfd, poll_table *pwait,
 }
 
 static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
-		   struct timespec *end_time)
+		   struct timespec64 *end_time)
 {
 	poll_table* pt = &wait->pt;
 	ktime_t expire, *to = NULL;
@@ -854,7 +860,7 @@ static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
 		 * pointer to the expiry value.
 		 */
 		if (end_time && !to) {
-			expire = timespec_to_ktime(*end_time);
+			expire = timespec64_to_ktime(*end_time);
 			to = &expire;
 		}
 
@@ -868,7 +874,7 @@ static int do_poll(struct poll_list *list, struct poll_wqueues *wait,
 			sizeof(struct pollfd))
 
 int do_sys_poll(struct pollfd __user *ufds, unsigned int nfds,
-		struct timespec *end_time)
+		struct timespec64 *end_time)
 {
 	struct poll_wqueues table;
  	int err = -EFAULT, fdcount, len, size;
@@ -936,7 +942,7 @@ static long do_restart_poll(struct restart_block *restart_block)
 {
 	struct pollfd __user *ufds = restart_block->poll.ufds;
 	int nfds = restart_block->poll.nfds;
-	struct timespec *to = NULL, end_time;
+	struct timespec64 *to = NULL, end_time;
 	int ret;
 
 	if (restart_block->poll.has_timeout) {
@@ -957,7 +963,7 @@ static long do_restart_poll(struct restart_block *restart_block)
 SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds,
 		int, timeout_msecs)
 {
-	struct timespec end_time, *to = NULL;
+	struct timespec64 end_time, *to = NULL;
 	int ret;
 
 	if (timeout_msecs >= 0) {
@@ -993,7 +999,8 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
 		size_t, sigsetsize)
 {
 	sigset_t ksigmask, sigsaved;
-	struct timespec ts, end_time, *to = NULL;
+	struct timespec ts;
+	struct timespec64 end_time, *to = NULL;
 	int ret;
 
 	if (tsp) {
diff --git a/include/linux/poll.h b/include/linux/poll.h
index 9fb4f40..37b057b 100644
--- a/include/linux/poll.h
+++ b/include/linux/poll.h
@@ -96,7 +96,7 @@ extern void poll_initwait(struct poll_wqueues *pwq);
 extern void poll_freewait(struct poll_wqueues *pwq);
 extern int poll_schedule_timeout(struct poll_wqueues *pwq, int state,
 				 ktime_t *expires, unsigned long slack);
-extern u64 select_estimate_accuracy(struct timespec *tv);
+extern u64 select_estimate_accuracy(struct timespec64 *tv);

 static inline int poll_schedule(struct poll_wqueues *pwq, int state)
@@ -153,12 +153,13 @@ void zero_fd_set(unsigned long nr, unsigned long *fdset)
 
 #define MAX_INT64_SECONDS (((s64)(~((u64)0)>>1)/HZ)-1)
 
-extern int do_select(int n, fd_set_bits *fds, struct timespec *end_time);
+extern int do_select(int n, fd_set_bits *fds, struct timespec64 *end_time);
 extern int do_sys_poll(struct pollfd __user * ufds, unsigned int nfds,
-		       struct timespec *end_time);
+		       struct timespec64 *end_time);
 extern int core_sys_select(int n, fd_set __user *inp, fd_set __user *outp,
-			   fd_set __user *exp, struct timespec *end_time);
+			   fd_set __user *exp, struct timespec64 *end_time);
 
-extern int poll_select_set_timeout(struct timespec *to, long sec, long nsec);
+extern int poll_select_set_timeout(struct timespec64 *to, time64_t sec,
+				   long nsec);
 
 #endif /* _LINUX_POLL_H */
diff --git a/net/socket.c b/net/socket.c
index 5dbb0bb..bdfe115 100644
--- a/net/socket.c
+++ b/net/socket.c
@@ -2171,7 +2171,8 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 	struct mmsghdr __user *entry;
 	struct compat_mmsghdr __user *compat_entry;
 	struct msghdr msg_sys;
-	struct timespec end_time;
+	struct timespec64 end_time;
+	struct timespec64 timeout64;
 
 	if (timeout &&
 	    poll_select_set_timeout(&end_time, timeout->tv_sec,
@@ -2223,8 +2224,9 @@ int __sys_recvmmsg(int fd, struct mmsghdr __user *mmsg, unsigned int vlen,
 			flags |= MSG_DONTWAIT;
 
 		if (timeout) {
-			ktime_get_ts(timeout);
-			*timeout = timespec_sub(end_time, *timeout);
+			ktime_get_ts64(&timeout64);
+			*timeout = timespec64_to_timespec(
+					timespec64_sub(end_time, timeout64));
 			if (timeout->tv_sec < 0) {
 				timeout->tv_sec = timeout->tv_nsec = 0;
 				break;
-- 
1.9.1

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