generic compat_sys_rt_sigprocmask()

conditional on GENERIC_COMPAT_RT_SIGPROCMASK; by the end of that series
it will become the same thing as COMPAT and conditional will die out.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 41 insertions, 0 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index 4a0934e03d5..bce1222b731 100644
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2613,6 +2613,47 @@ SYSCALL_DEFINE4(rt_sigprocmask, int, how, sigset_t __user *, nset,
 	return 0;
 }
 
+#ifdef CONFIG_COMPAT
+#ifdef CONFIG_GENERIC_COMPAT_RT_SIGPROCMASK
+COMPAT_SYSCALL_DEFINE4(rt_sigprocmask, int, how, compat_sigset_t __user *, nset,
+		compat_sigset_t __user *, oset, compat_size_t, sigsetsize)
+{
+#ifdef __BIG_ENDIAN
+	sigset_t old_set = current->blocked;
+
+	/* XXX: Don't preclude handling different sized sigset_t's.  */
+	if (sigsetsize != sizeof(sigset_t))
+		return -EINVAL;
+
+	if (nset) {
+		compat_sigset_t new32;
+		sigset_t new_set;
+		int error;
+		if (copy_from_user(&new32, nset, sizeof(compat_sigset_t)))
+			return -EFAULT;
+
+		sigset_from_compat(&new_set, &new32);
+		sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
+
+		error = sigprocmask(how, &new_set, NULL);
+		if (error)
+			return error;
+	}
+	if (oset) {
+		compat_sigset_t old32;
+		sigset_to_compat(&old32, &old_set);
+		if (copy_to_user(oset, &old_set, sizeof(sigset_t)))
+			return -EFAULT;
+	}
+	return 0;
+#else
+	return sys_rt_sigprocmask(how, (sigset_t __user *)nset,
+				  (sigset_t __user *)oset, sigsetsize);
+#endif
+}
+#endif
+#endif
+
 long do_sigpending(void __user *set, unsigned long sigsetsize)
 {
 	long error = -EINVAL;