Commit b772434b authored by Oleg Nesterov's avatar Oleg Nesterov Committed by Linus Torvalds
Browse files

signal: simplify set_user_sigmask/restore_user_sigmask 

task->saved_sigmask and ->restore_sigmask are only used in the ret-from-
syscall paths.  This means that set_user_sigmask() can save ->blocked in
->saved_sigmask and do set_restore_sigmask() to indicate that ->blocked
was modified.

This way the callers do not need 2 sigset_t's passed to set/restore and
restore_user_sigmask() renamed to restore_saved_sigmask_unless() turns
into the trivial helper which just calls restore_saved_sigmask().

Link: http://lkml.kernel.org/r/20190606113206.GA9464@redhat.com


Signed-off-by: default avatarOleg Nesterov <oleg@redhat.com>
Cc: Deepa Dinamani <deepa.kernel@gmail.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Eric Wong <e@80x24.org>
Cc: Jason Baron <jbaron@akamai.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: David Laight <David.Laight@aculab.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent e2d9018e

fs/aio.c

+8 −12
Original line number Diff line number Diff line
@@ -2094,7 +2094,6 @@ SYSCALL_DEFINE6(io_pgetevents, 
		const struct __aio_sigset __user *, usig)

{

	struct __aio_sigset	ksig = { NULL, };

	sigset_t		ksigmask, sigsaved;

	struct timespec64	ts;

	bool interrupted;

	int ret;
@@ -2105,14 +2104,14 @@ SYSCALL_DEFINE6(io_pgetevents, 
	if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))

		return -EFAULT;



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

	ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);

	if (ret)

		return ret;



	ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);



	interrupted = signal_pending(current);

	restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);

	restore_saved_sigmask_unless(interrupted);

	if (interrupted && !ret)

		ret = -ERESTARTNOHAND;
@@ -2130,7 +2129,6 @@ SYSCALL_DEFINE6(io_pgetevents_time32, 
		const struct __aio_sigset __user *, usig)

{

	struct __aio_sigset	ksig = { NULL, };

	sigset_t		ksigmask, sigsaved;

	struct timespec64	ts;

	bool interrupted;

	int ret;
@@ -2142,14 +2140,14 @@ SYSCALL_DEFINE6(io_pgetevents_time32, 
		return -EFAULT;





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

	ret = set_user_sigmask(ksig.sigmask, ksig.sigsetsize);

	if (ret)

		return ret;



	ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &ts : NULL);



	interrupted = signal_pending(current);

	restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);

	restore_saved_sigmask_unless(interrupted);

	if (interrupted && !ret)

		ret = -ERESTARTNOHAND;
@@ -2198,7 +2196,6 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents, 
		const struct __compat_aio_sigset __user *, usig)

{

	struct __compat_aio_sigset ksig = { NULL, };

	sigset_t ksigmask, sigsaved;

	struct timespec64 t;

	bool interrupted;

	int ret;
@@ -2209,14 +2206,14 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents, 
	if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))

		return -EFAULT;



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

	ret = set_compat_user_sigmask(ksig.sigmask, ksig.sigsetsize);

	if (ret)

		return ret;



	ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);



	interrupted = signal_pending(current);

	restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);

	restore_saved_sigmask_unless(interrupted);

	if (interrupted && !ret)

		ret = -ERESTARTNOHAND;
@@ -2234,7 +2231,6 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64, 
		const struct __compat_aio_sigset __user *, usig)

{

	struct __compat_aio_sigset ksig = { NULL, };

	sigset_t ksigmask, sigsaved;

	struct timespec64 t;

	bool interrupted;

	int ret;
@@ -2245,14 +2241,14 @@ COMPAT_SYSCALL_DEFINE6(io_pgetevents_time64, 
	if (usig && copy_from_user(&ksig, usig, sizeof(ksig)))

		return -EFAULT;



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

	ret = set_compat_user_sigmask(ksig.sigmask, ksig.sigsetsize);

	if (ret)

		return ret;



	ret = do_io_getevents(ctx_id, min_nr, nr, events, timeout ? &t : NULL);



	interrupted = signal_pending(current);

	restore_user_sigmask(ksig.sigmask, &sigsaved, interrupted);

	restore_saved_sigmask_unless(interrupted);

	if (interrupted && !ret)

		ret = -ERESTARTNOHAND;

fs/eventpoll.c

+4 −8
Original line number Diff line number Diff line
@@ -2313,19 +2313,17 @@ SYSCALL_DEFINE6(epoll_pwait, int, epfd, struct epoll_event __user *, events, 
		size_t, sigsetsize)

{

	int error;

	sigset_t ksigmask, sigsaved;



	/*

	 * If the caller wants a certain signal mask to be set during the wait,

	 * we apply it here.

	 */

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

	error = set_user_sigmask(sigmask, sigsetsize);

	if (error)

		return error;



	error = do_epoll_wait(epfd, events, maxevents, timeout);



	restore_user_sigmask(sigmask, &sigsaved, error == -EINTR);

	restore_saved_sigmask_unless(error == -EINTR);



	return error;

}
@@ -2338,19 +2336,17 @@ COMPAT_SYSCALL_DEFINE6(epoll_pwait, int, epfd, 
			compat_size_t, sigsetsize)

{

	long err;

	sigset_t ksigmask, sigsaved;



	/*

	 * If the caller wants a certain signal mask to be set during the wait,

	 * we apply it here.

	 */

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

	err = set_compat_user_sigmask(sigmask, sigsetsize);

	if (err)

		return err;



	err = do_epoll_wait(epfd, events, maxevents, timeout);



	restore_user_sigmask(sigmask, &sigsaved, err == -EINTR);

	restore_saved_sigmask_unless(err == -EINTR);



	return err;

}

fs/io_uring.c

+3 −8
Original line number Diff line number Diff line
@@ -2400,7 +2400,6 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
			  const sigset_t __user *sig, size_t sigsz)

{

	struct io_cq_ring *ring = ctx->cq_ring;

	sigset_t ksigmask, sigsaved;

	int ret;



	if (io_cqring_events(ring) >= min_events)
@@ -2410,21 +2409,17 @@ static int io_cqring_wait(struct io_ring_ctx *ctx, int min_events, 
#ifdef CONFIG_COMPAT

		if (in_compat_syscall())

			ret = set_compat_user_sigmask((const compat_sigset_t __user *)sig,

						      &ksigmask, &sigsaved, sigsz);

						      sigsz);

		else

#endif

			ret = set_user_sigmask(sig, &ksigmask,

					       &sigsaved, sigsz);

			ret = set_user_sigmask(sig, sigsz);



		if (ret)

			return ret;

	}



	ret = wait_event_interruptible(ctx->wait, io_cqring_events(ring) >= min_events);



	if (sig)

		restore_user_sigmask(sig, &sigsaved, ret == -ERESTARTSYS);



	restore_saved_sigmask_unless(ret == -ERESTARTSYS);

	if (ret == -ERESTARTSYS)

		ret = -EINTR;

fs/select.c

+12 −22
Original line number Diff line number Diff line
@@ -730,7 +730,6 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 
		       const sigset_t __user *sigmask, size_t sigsetsize,

		       enum poll_time_type type)

{

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;
@@ -753,12 +752,12 @@ static long do_pselect(int n, fd_set __user *inp, fd_set __user *outp, 
			return -EINVAL;

	}



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

	ret = set_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



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

	restore_user_sigmask(sigmask, &sigsaved, ret == -ERESTARTNOHAND);

	restore_saved_sigmask_unless(ret == -ERESTARTNOHAND);

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



	return ret;
@@ -1086,7 +1085,6 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 
		struct __kernel_timespec __user *, tsp, const sigset_t __user *, sigmask,

		size_t, sigsetsize)

{

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;
@@ -1099,17 +1097,16 @@ SYSCALL_DEFINE5(ppoll, struct pollfd __user *, ufds, unsigned int, nfds, 
			return -EINVAL;

	}



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

	ret = set_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



	ret = do_sys_poll(ufds, nfds, to);



	restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);

	restore_saved_sigmask_unless(ret == -EINTR);

	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



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



	return ret;
@@ -1121,7 +1118,6 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, 
		struct old_timespec32 __user *, tsp, const sigset_t __user *, sigmask,

		size_t, sigsetsize)

{

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;
@@ -1134,17 +1130,16 @@ SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, unsigned int, nfds, 
			return -EINVAL;

	}



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

	ret = set_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



	ret = do_sys_poll(ufds, nfds, to);



	restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);

	restore_saved_sigmask_unless(ret == -EINTR);

	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



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



	return ret;
@@ -1319,7 +1314,6 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, 
	void __user *tsp, compat_sigset_t __user *sigmask,

	compat_size_t sigsetsize, enum poll_time_type type)

{

	sigset_t ksigmask, sigsaved;

	struct timespec64 ts, end_time, *to = NULL;

	int ret;
@@ -1342,12 +1336,12 @@ static long do_compat_pselect(int n, compat_ulong_t __user *inp, 
			return -EINVAL;

	}



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

	ret = set_compat_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



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

	restore_user_sigmask(sigmask, &sigsaved, ret == -ERESTARTNOHAND);

	restore_saved_sigmask_unless(ret == -ERESTARTNOHAND);

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



	return ret;
@@ -1402,7 +1396,6 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, 
	unsigned int,  nfds, struct old_timespec32 __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;
@@ -1415,17 +1408,16 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time32, struct pollfd __user *, ufds, 
			return -EINVAL;

	}



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

	ret = set_compat_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



	ret = do_sys_poll(ufds, nfds, to);



	restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);

	restore_saved_sigmask_unless(ret == -EINTR);

	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



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



	return ret;
@@ -1437,7 +1429,6 @@ 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;
@@ -1450,17 +1441,16 @@ COMPAT_SYSCALL_DEFINE5(ppoll_time64, struct pollfd __user *, ufds, 
			return -EINVAL;

	}



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

	ret = set_compat_user_sigmask(sigmask, sigsetsize);

	if (ret)

		return ret;



	ret = do_sys_poll(ufds, nfds, to);



	restore_user_sigmask(sigmask, &sigsaved, ret == -EINTR);

	restore_saved_sigmask_unless(ret == -EINTR);

	/* We can restart this syscall, usually */

	if (ret == -EINTR)

		ret = -ERESTARTNOHAND;



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



	return ret;

include/linux/compat.h

+1 −2
Original line number Diff line number Diff line
@@ -138,8 +138,7 @@ typedef struct { 
	compat_sigset_word	sig[_COMPAT_NSIG_WORDS];

} compat_sigset_t;



int set_compat_user_sigmask(const compat_sigset_t __user *usigmask,

			    sigset_t *set, sigset_t *oldset,

int set_compat_user_sigmask(const compat_sigset_t __user *umask,

			    size_t sigsetsize);



struct compat_sigaction {

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