select: Use get/put_timespec64

Usage of these apis and their compat versions makes
the syscalls: select family of syscalls and their
compat implementations simpler.

This is a preparatory patch to isolate data conversions to
struct timespec64 at userspace boundaries. This helps contain
the changes needed to transition to new y2038 safe types.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 24 insertions, 36 deletions

diff --git a/fs/select.c b/fs/select.c
index c6362e38ae92..20a7d061904f 100644
--- a/fs/select.c
+++ b/fs/select.c
@@ -291,8 +291,7 @@ static int poll_select_copy_remaining(struct timespec64 *end_time,
                                       void __user *p,
                                       int timeval, int ret)
 {
-        struct timespec64 rts64;
-        struct timespec rts;
+        struct timespec64 rts;
         struct timeval rtv;
 
         if (!p)
@@ -305,23 +304,22 @@ static int poll_select_copy_remaining(struct timespec64 *end_time,
         if (!end_time->tv_sec && !end_time->tv_nsec)
                 return ret;
 
-        ktime_get_ts64(&rts64);
-        rts64 = timespec64_sub(*end_time, rts64);
-        if (rts64.tv_sec < 0)
-                rts64.tv_sec = rts64.tv_nsec = 0;
+        ktime_get_ts64(&rts);
+        rts = timespec64_sub(*end_time, rts);
+        if (rts.tv_sec < 0)
+                rts.tv_sec = rts.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 = rts64.tv_sec;
-                rtv.tv_usec = rts64.tv_nsec / NSEC_PER_USEC;
+                rtv.tv_sec = rts.tv_sec;
+                rtv.tv_usec = rts.tv_nsec / NSEC_PER_USEC;
 
                 if (!copy_to_user(p, &rtv, sizeof(rtv)))
                         return ret;
 
-        } else if (!copy_to_user(p, &rts, sizeof(rts)))
+        } else if (!put_timespec64(&rts, p))
                 return ret;
 
         /*
@@ -704,17 +702,15 @@ 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;
-        struct timespec64 ts64, end_time, *to = NULL;
+        struct timespec64 ts, end_time, *to = NULL;
         int ret;
 
         if (tsp) {
-                if (copy_from_user(&ts, tsp, sizeof(ts)))
+                if (get_timespec64(&ts, tsp))
                         return -EFAULT;
-                ts64 = timespec_to_timespec64(ts);
 
                 to = &end_time;
-                if (poll_select_set_timeout(to, ts64.tv_sec, ts64.tv_nsec))
+                if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))
                         return -EINVAL;
         }
 
@@ -1051,12 +1047,11 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
                 size_t, sigsetsize)
 {
         sigset_t ksigmask, sigsaved;
-        struct timespec ts;
-        struct timespec64 end_time, *to = NULL;
+        struct timespec64 ts, end_time, *to = NULL;
         int ret;
 
         if (tsp) {
-                if (copy_from_user(&ts, tsp, sizeof(ts)))
+                if (get_timespec64(&ts, tsp))
                         return -EFAULT;
 
                 to = &end_time;
@@ -1102,10 +1097,10 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,
 #define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))
 
 static
-int compat_poll_select_copy_remaining(struct timespec *end_time, void __user *p,
+int compat_poll_select_copy_remaining(struct timespec64 *end_time, void __user *p,
                                       int timeval, int ret)
 {
-        struct timespec ts;
+        struct timespec64 ts;
 
         if (!p)
                 return ret;
@@ -1117,8 +1112,8 @@ int compat_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(&ts);
-        ts = timespec_sub(*end_time, ts);
+        ktime_get_ts64(&ts);
+        ts = timespec64_sub(*end_time, ts);
         if (ts.tv_sec < 0)
                 ts.tv_sec = ts.tv_nsec = 0;
 
@@ -1131,12 +1126,7 @@ int compat_poll_select_copy_remaining(struct timespec *end_time, void __user *p,
                 if (!copy_to_user(p, &rtv, sizeof(rtv)))
                         return ret;
         } else {
-                struct compat_timespec rts;
-
-                rts.tv_sec = ts.tv_sec;
-                rts.tv_nsec = ts.tv_nsec;
-
-                if (!copy_to_user(p, &rts, sizeof(rts)))
+                if (!compat_put_timespec64(&ts, p))
                         return ret;
         }
         /*
@@ -1194,7 +1184,7 @@ int compat_set_fd_set(unsigned long nr, compat_ulong_t __user *ufdset,
  */
 static int compat_core_sys_select(int n, compat_ulong_t __user *inp,
         compat_ulong_t __user *outp, compat_ulong_t __user *exp,
-        struct timespec *end_time)
+        struct timespec64 *end_time)
 {
         fd_set_bits fds;
         void *bits;
@@ -1267,7 +1257,7 @@ COMPAT_SYSCALL_DEFINE5(select, int, n, compat_ulong_t __user *, inp,
         compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,
         struct compat_timeval __user *, tvp)
 {
-        struct timespec end_time, *to = NULL;
+        struct timespec64 end_time, *to = NULL;
         struct compat_timeval tv;
         int ret;
 
@@ -1313,12 +1303,11 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp,
 {
         compat_sigset_t ss32;
         sigset_t ksigmask, sigsaved;
-        struct compat_timespec ts;
-        struct timespec end_time, *to = NULL;
+        struct timespec64 ts, end_time, *to = NULL;
         int ret;
 
         if (tsp) {
-                if (copy_from_user(&ts, tsp, sizeof(ts)))
+                if (compat_get_timespec64(&ts, tsp))
                         return -EFAULT;
 
                 to = &end_time;
@@ -1382,12 +1371,11 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,
 {
         compat_sigset_t ss32;
         sigset_t ksigmask, sigsaved;
-        struct compat_timespec ts;
-        struct timespec end_time, *to = NULL;
+        struct timespec64 ts, end_time, *to = NULL;
         int ret;
 
         if (tsp) {
-                if (copy_from_user(&ts, tsp, sizeof(ts)))
+                if (compat_get_timespec64(&ts, tsp))
                         return -EFAULT;
 
                 to = &end_time;