Commit 7e71609f authored by Al Viro's avatar Al Viro
Browse files

pselect6() and friends: take handling the combined 6th/7th args into helper 



... and use unsafe_get_user(), while we are at it.

Signed-off-by: default avatarAl Viro <viro@zeniv.linux.org.uk>
parent b44f6873

fs/select.c

+64 −48
Original line number Diff line number Diff line
@@ -766,22 +766,38 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 
 * which has a pointer to the sigset_t itself followed by a size_t containing

 * the sigset size.

 */

struct sigset_argpack {

	sigset_t __user *p;

	size_t size;

};



static inline int get_sigset_argpack(struct sigset_argpack *to,

				     struct sigset_argpack __user *from)

{

	// the path is hot enough for overhead of copy_from_user() to matter

	if (from) {

		if (!user_read_access_begin(from, sizeof(*from)))

			return -EFAULT;

		unsafe_get_user(to->p, &from->p, Efault);

		unsafe_get_user(to->size, &from->size, Efault);

		user_read_access_end();

	}

	return 0;

Efault:

	user_access_end();

	return -EFAULT;

}



SYSCALL_DEFINE6(pselect6, int, n, fd_set __user *, inp, fd_set __user *, outp,

		fd_set __user *, exp, struct __kernel_timespec __user *, tsp,

		void __user *, sig)

{

	size_t sigsetsize = 0;

	sigset_t __user *up = NULL;



	if (sig) {

		if (!access_ok(sig, sizeof(void *)+sizeof(size_t))

		    || __get_user(up, (sigset_t __user * __user *)sig)

		    || __get_user(sigsetsize,

				(size_t __user *)(sig+sizeof(void *))))

	struct sigset_argpack x = {NULL, 0};



	if (get_sigset_argpack(&x, sig))

		return -EFAULT;

	}



	return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_TIMESPEC);

	return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_TIMESPEC);

}



#if defined(CONFIG_COMPAT_32BIT_TIME) && !defined(CONFIG_64BIT)
@@ -790,18 +806,12 @@ SYSCALL_DEFINE6(pselect6_time32, int, n, fd_set __user *, inp, fd_set __user *, 
		fd_set __user *, exp, struct old_timespec32 __user *, tsp,

		void __user *, sig)

{

	size_t sigsetsize = 0;

	sigset_t __user *up = NULL;



	if (sig) {

		if (!access_ok(sig, sizeof(void *)+sizeof(size_t))

		    || __get_user(up, (sigset_t __user * __user *)sig)

		    || __get_user(sigsetsize,

				(size_t __user *)(sig+sizeof(void *))))

	struct sigset_argpack x = {NULL, 0};



	if (get_sigset_argpack(&x, sig))

		return -EFAULT;

	}



	return do_pselect(n, inp, outp, exp, tsp, up, sigsetsize, PT_OLD_TIMESPEC);

	return do_pselect(n, inp, outp, exp, tsp, x.p, x.size, PT_OLD_TIMESPEC);

}



#endif
@@ -1325,24 +1335,37 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, 
	return poll_select_finish(&end_time, tsp, type, ret);

}



struct compat_sigset_argpack {

	compat_uptr_t p;

	compat_size_t size;

};

static inline int get_compat_sigset_argpack(struct compat_sigset_argpack *to,

					    struct compat_sigset_argpack __user *from)

{

	if (from) {

		if (!user_read_access_begin(from, sizeof(*from)))

			return -EFAULT;

		unsafe_get_user(to->p, &from->p, Efault);

		unsafe_get_user(to->size, &from->size, Efault);

		user_read_access_end();

	}

	return 0;

Efault:

	user_access_end();

	return -EFAULT;

}



COMPAT_SYSCALL_DEFINE6(pselect6_time64, int, n, compat_ulong_t __user *, inp,

	compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,

	struct __kernel_timespec __user *, tsp, void __user *, sig)

{

	compat_size_t sigsetsize = 0;

	compat_uptr_t up = 0;



	if (sig) {

		if (!access_ok(sig,

				sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||

				__get_user(up, (compat_uptr_t __user *)sig) ||

				__get_user(sigsetsize,

				(compat_size_t __user *)(sig+sizeof(up))))

	struct compat_sigset_argpack x = {0, 0};



	if (get_compat_sigset_argpack(&x, sig))

		return -EFAULT;

	}



	return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up),

				 sigsetsize, PT_TIMESPEC);

	return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),

				 x.size, PT_TIMESPEC);

}



#if defined(CONFIG_COMPAT_32BIT_TIME)
@@ -1351,20 +1374,13 @@ COMPAT_SYSCALL_DEFINE6(pselect6_time32, int, n, compat_ulong_t __user *, inp, 
	compat_ulong_t __user *, outp, compat_ulong_t __user *, exp,

	struct old_timespec32 __user *, tsp, void __user *, sig)

{

	compat_size_t sigsetsize = 0;

	compat_uptr_t up = 0;



	if (sig) {

		if (!access_ok(sig,

				sizeof(compat_uptr_t)+sizeof(compat_size_t)) ||

		    	__get_user(up, (compat_uptr_t __user *)sig) ||

		    	__get_user(sigsetsize,

				(compat_size_t __user *)(sig+sizeof(up))))

	struct compat_sigset_argpack x = {0, 0};



	if (get_compat_sigset_argpack(&x, sig))

		return -EFAULT;

	}



	return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(up),

				 sigsetsize, PT_OLD_TIMESPEC);

	return do_compat_pselect(n, inp, outp, exp, tsp, compat_ptr(x.p),

				 x.size, PT_OLD_TIMESPEC);

}



#endif