[PATCH 1/2] select: Use get/put_timespec64

From: Deepa Dinamani
Date: Sat Aug 05 2017 - 00:13:39 EST


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@xxxxxxxxx>
---
fs/select.c | 60 ++++++++++++++++++++++++------------------------------------
1 file changed, 24 insertions(+), 36 deletions(-)

diff --git a/fs/select.c b/fs/select.c
index 9d5f15ed87fe..0cf17fb33cf7 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;
}
/*
@@ -1198,7 +1188,7 @@ 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;
@@ -1271,7 +1261,7 @@ 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;

@@ -1317,12 +1307,11 @@ 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;
@@ -1386,12 +1375,11 @@ 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;
--
2.11.0