Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 8bd27a30 authored by Deepa Dinamani's avatar Deepa Dinamani Committed by Arnd Bergmann
Browse files

ppoll: use __kernel_timespec 



struct timespec is not y2038 safe.
struct __kernel_timespec is the new y2038 safe structure for all
syscalls that are using struct timespec.
Update ppoll interfaces to use struct __kernel_timespec.

sigset_t also has different representations on 32 bit and 64 bit
architectures. Hence, we need to support the following different
syscalls:

New y2038 safe syscalls:
(Controlled by CONFIG_64BIT_TIME for 32 bit ABIs)

Native 64 bit(unchanged) and native 32 bit : sys_ppoll
Compat : compat_sys_ppoll_time64

Older y2038 unsafe syscalls:
(Controlled by CONFIG_32BIT_COMPAT_TIME for 32 bit ABIs)

Native 32 bit : ppoll_time32
Compat : compat_sys_ppoll

Signed-off-by: default avatarDeepa Dinamani <deepa.kernel@gmail.com>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
parent 854a6ed5

fs/select.c

+111 −55
Original line number Diff line number Diff line
@@ -287,12 +287,18 @@ int poll_select_set_timeout(struct timespec64 *to, time64_t sec, long nsec) 
	return 0;

}



enum poll_time_type {

	PT_TIMEVAL = 0,

	PT_OLD_TIMEVAL = 1,

	PT_TIMESPEC = 2,

	PT_OLD_TIMESPEC = 3,

};



static int poll_select_copy_remaining(struct timespec64 *end_time,

				      void __user *p,

				      int timeval, int ret)

				      enum poll_time_type pt_type, int ret)

{

	struct timespec64 rts;

	struct timeval rtv;



	if (!p)

		return ret;
@@ -310,18 +316,40 @@ static int poll_select_copy_remaining(struct timespec64 *end_time, 
		rts.tv_sec = rts.tv_nsec = 0;





	if (timeval) {

	switch (pt_type) {

	case PT_TIMEVAL:

		{

			struct timeval rtv;



			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;



			if (!copy_to_user(p, &rtv, sizeof(rtv)))

				return ret;

		}

		break;

	case PT_OLD_TIMEVAL:

		{

			struct old_timeval32 rtv;



	} else if (!put_timespec64(&rts, p))

			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;



		}

		break;

	case PT_TIMESPEC:

		if (!put_timespec64(&rts, p))

			return ret;

		break;

	case PT_OLD_TIMESPEC:

		if (!put_old_timespec32(&rts, p))

			return ret;

		break;

	default:

		BUG();

	}

	/*

	 * If an application puts its timeval in read-only memory, we

	 * don't want the Linux-specific update to the timeval to
@@ -689,7 +717,7 @@ static int kern_select(int n, fd_set __user *inp, fd_set __user *outp, 
	}



	ret = core_sys_select(n, inp, outp, exp, to);

	ret = poll_select_copy_remaining(&end_time, tvp, 1, ret);

	ret = poll_select_copy_remaining(&end_time, tvp, PT_TIMEVAL, ret);



	return ret;

}
@@ -722,7 +750,7 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 
		return ret;



	ret = core_sys_select(n, inp, outp, exp, to);

	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

	ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);



	restore_user_sigmask(sigmask, &sigsaved);
@@ -1026,7 +1054,7 @@ SYSCALL_DEFINE3(poll, struct pollfd __user *, ufds, unsigned int, nfds, 
}



SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds,

		struct timespec __user *, tsp, const sigset_t __user *, sigmask,

		struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask,

		size_t, sigsetsize)

{

	sigset_t ksigmask, sigsaved;
@@ -1054,60 +1082,50 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 
	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



	ret = poll_select_copy_remaining(&end_time, tsp, 0, ret);

	ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);



	return ret;

}



#ifdef CONFIG_COMPAT

#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))

#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)



static

int compat_poll_select_copy_remaining(struct timespec64 *end_time, void __user *p,

				      int timeval, int ret)

SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds,

		struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask,

		size_t, sigsetsize)

{

	struct timespec64 ts;

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;



	if (!p)

		return ret;

	if (tsp) {

		if (get_old_timespec32(&ts, tsp))

			return -EFAULT;



	if (current->personality & STICKY_TIMEOUTS)

		goto sticky;

		to = &end_time;

		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))

			return -EINVAL;

	}



	/* No update for zero timeout */

	if (!end_time->tv_sec && !end_time->tv_nsec)

	ret = set_user_sigmask(sigmask, &ksigmask, &sigsaved, sigsetsize);

	if (ret)

		return ret;



	ktime_get_ts64(&ts);

	ts = timespec64_sub(*end_time, ts);

	if (ts.tv_sec < 0)

		ts.tv_sec = ts.tv_nsec = 0;

	ret = do_sys_poll(ufds, nfds, to);



	if (timeval) {

		struct old_timeval32 rtv;

	restore_user_sigmask(sigmask, &sigsaved);



		rtv.tv_sec = ts.tv_sec;

		rtv.tv_usec = ts.tv_nsec / NSEC_PER_USEC;

	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



		if (!copy_to_user(p, &rtv, sizeof(rtv)))

			return ret;

	} else {

		if (!put_old_timespec32(&ts, p))

			return ret;

	}

	/*

	 * If an application puts its timeval in read-only memory, we

	 * don't want the Linux-specific update to the timeval to

	 * cause a fault after the select has completed

	 * successfully. However, because we're not updating the

	 * timeval, we can't restart the system call.

	 */

	ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);



sticky:

	if (ret == -ERESTARTNOHAND)

		ret = -EINTR;

	return ret;

}

#endif



#ifdef CONFIG_COMPAT

#define __COMPAT_NFDBITS       (8 * sizeof(compat_ulong_t))



/*

 * Ooo, nasty.  We need here to frob 32-bit unsigned longs to
@@ -1239,7 +1257,7 @@ static int do_compat_select(int n, compat_ulong_t __user *inp, 
	}



	ret = compat_core_sys_select(n, inp, outp, exp, to);

	ret = compat_poll_select_copy_remaining(&end_time, tvp, 1, ret);

	ret = poll_select_copy_remaining(&end_time, tvp, PT_OLD_TIMEVAL, ret);



	return ret;

}
@@ -1292,7 +1310,7 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, 
		return ret;



	ret = compat_core_sys_select(n, inp, outp, exp, to);

	ret = compat_poll_select_copy_remaining(&end_time, tsp, 0, ret);

	ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);



	restore_user_sigmask(sigmask, &sigsaved);
@@ -1318,6 +1336,7 @@ COMPAT_SYSCALL_DEFINE6(pselect6, int, n, compat_ulong_t __user *, inp, 
				 sigsetsize);

}



#if defined(CONFIG_COMPAT_32BIT_TIME)

COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds,

	unsigned int,  nfds, struct old_timespec32 __user *, tsp,

	const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)
@@ -1347,8 +1366,45 @@ COMPAT_SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, 
	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



	ret = compat_poll_select_copy_remaining(&end_time, tsp, 0, ret);

	ret = poll_select_copy_remaining(&end_time, tsp, PT_OLD_TIMESPEC, ret);



	return ret;

}

#endif



/* New compat syscall for 64 bit time_t*/

COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds,

	unsigned int,  nfds, struct __kernel_timespec __user *, tsp,

	const compat_sigset_t __user *, sigmask, compat_size_t, sigsetsize)

{

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;



	if (tsp) {

		if (get_timespec64(&ts, tsp))

			return -EFAULT;



		to = &end_time;

		if (poll_select_set_timeout(to, ts.tv_sec, ts.tv_nsec))

			return -EINVAL;

	}



	ret = set_compat_user_sigmask(sigmask, &ksigmask, &sigsaved, sigsetsize);

	if (ret)

		return ret;



	ret = do_sys_poll(ufds, nfds, to);



	restore_user_sigmask(sigmask, &sigsaved);



	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



	ret = poll_select_copy_remaining(&end_time, tsp, PT_TIMESPEC, ret);



	return ret;

}



#endif

include/linux/compat.h

+5 −0
Original line number Diff line number Diff line
@@ -652,6 +652,11 @@ asmlinkage long compat_sys_ppoll(struct pollfd __user *ufds, 
				 struct old_timespec32 __user *tsp,

				 const compat_sigset_t __user *sigmask,

				 compat_size_t sigsetsize);

asmlinkage long compat_sys_ppoll_time64(struct pollfd __user *ufds,

				 unsigned int nfds,

				 struct __kernel_timespec __user *tsp,

				 const compat_sigset_t __user *sigmask,

				 compat_size_t sigsetsize);



/* fs/signalfd.c */

asmlinkage long compat_sys_signalfd4(int ufd,

include/linux/syscalls.h

+4 −1
Original line number Diff line number Diff line
@@ -469,7 +469,10 @@ asmlinkage long sys_pselect6(int, fd_set __user *, fd_set __user *, 
			     fd_set __user *, struct timespec __user *,

			     void __user *);

asmlinkage long sys_ppoll(struct pollfd __user *, unsigned int,

			  struct timespec __user *, const sigset_t __user *,

			  struct __kernel_timespec __user *, const sigset_t __user *,

			  size_t);

asmlinkage long sys_ppoll_time32(struct pollfd __user *, unsigned int,

			  struct old_timespec32 __user *, const sigset_t __user *,

			  size_t);



/* fs/signalfd.c */