[RFC PATCH 1/5] signal: Teach sigsuspend to use set_user_sigmask

[ebiederm@xxxxxxxxxxxx (Eric W. Biederman)]

The sigsuspend system call overrides the signal mask just
like all of the other users of set_user_sigmask, so convert
it to use the same helpers.

Signed-off-by: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
---
 kernel/signal.c | 43 +++++++++++++++++++------------------------
 1 file changed, 19 insertions(+), 24 deletions(-)

diff --git a/kernel/signal.c b/kernel/signal.c
index 6f72cff043f0..bfa36320a4f7 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2932,6 +2932,15 @@ int sigprocmask(int how, sigset_t *set, sigset_t *oldset)
 }
 EXPORT_SYMBOL(sigprocmask);
 
+static int set_sigmask(sigset_t *kmask)
+{
+	set_restore_sigmask();
+	current->saved_sigmask = current->blocked;
+	set_current_blocked(kmask);
+
+	return 0;
+}
+
 /*
  * The api helps set app-provided sigmasks.
  *
@@ -2952,11 +2961,7 @@ int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize)
 	if (copy_from_user(&kmask, umask, sizeof(sigset_t)))
 		return -EFAULT;
 
-	set_restore_sigmask();
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(&kmask);
-
-	return 0;
+	return set_sigmask(&kmask);
 }
 
 #ifdef CONFIG_COMPAT
@@ -2972,11 +2977,7 @@ int set_compat_user_sigmask(const compat_sigset_t __user *umask,
 	if (get_compat_sigset(&kmask, umask))
 		return -EFAULT;
 
-	set_restore_sigmask();
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(&kmask);
-
-	return 0;
+	return set_sigmask(&kmask);
 }
 #endif
 
@@ -4409,14 +4410,10 @@ SYSCALL_DEFINE0(pause)
 
 static int sigsuspend(sigset_t *set)
 {
-	current->saved_sigmask = current->blocked;
-	set_current_blocked(set);
-
 	while (!signal_pending(current)) {
 		__set_current_state(TASK_INTERRUPTIBLE);
 		schedule();
 	}
-	set_restore_sigmask();
 	return -ERESTARTNOHAND;
 }
 
@@ -4430,12 +4427,10 @@ SYSCALL_DEFINE2(rt_sigsuspend, sigset_t __user *, unewset, size_t, sigsetsize)
 {
 	sigset_t newset;
 
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (copy_from_user(&newset, unewset, sizeof(newset)))
+	set_user_sigmask(unewset, sigsetsize);
+	if (!unewset)
 		return -EFAULT;
+
 	return sigsuspend(&newset);
 }
  
@@ -4444,12 +4439,10 @@ COMPAT_SYSCALL_DEFINE2(rt_sigsuspend, compat_sigset_t __user *, unewset, compat_
 {
 	sigset_t newset;
 
-	/* XXX: Don't preclude handling different sized sigset_t's.  */
-	if (sigsetsize != sizeof(sigset_t))
-		return -EINVAL;
-
-	if (get_compat_sigset(&newset, unewset))
+	set_compat_user_sigmask(unewset, sigsetsize);
+	if (!unewset)
 		return -EFAULT;
+
 	return sigsuspend(&newset);
 }
 #endif
@@ -4459,6 +4452,7 @@ SYSCALL_DEFINE1(sigsuspend, old_sigset_t, mask)
 {
 	sigset_t blocked;
 	siginitset(&blocked, mask);
+	set_sigmask(&blocked);
 	return sigsuspend(&blocked);
 }
 #endif
@@ -4467,6 +4461,7 @@ SYSCALL_DEFINE3(sigsuspend, int, unused1, int, unused2, old_sigset_t, mask)
 {
 	sigset_t blocked;
 	siginitset(&blocked, mask);
+	set_sigmask(&blocked);
 	return sigsuspend(&blocked);
 }
 #endif
-- 
2.21.0.dirty