nvme: fix a possible deadlock when passthru commands sent to a multipath device

[linux.git] / kernel / signal.c

diff --git a/kernel/signal.c b/kernel/signal.c
index dabe100d209191cb6b15a6f80910e92b28553f11..91b789dd6e722ef96f8cf4440eb8f5bbc857ac60 100644 (file)
--- a/kernel/signal.c
+++ b/kernel/signal.c
@@ -2951,80 +2951,49 @@ EXPORT_SYMBOL(sigprocmask);
  *
  * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
  * epoll_pwait where a new sigmask is passed from userland for the syscalls.
+ *
+ * Note that it does set_restore_sigmask() in advance, so it must be always
+ * paired with restore_saved_sigmask_unless() before return from syscall.
  */
-int set_user_sigmask(const sigset_t __user *usigmask, sigset_t *set,
-                    sigset_t *oldset, size_t sigsetsize)
+int set_user_sigmask(const sigset_t __user *umask, size_t sigsetsize)
 {
-       if (!usigmask)
-               return 0;
+       sigset_t kmask;
 
+       if (!umask)
+               return 0;
        if (sigsetsize != sizeof(sigset_t))
                return -EINVAL;
-       if (copy_from_user(set, usigmask, sizeof(sigset_t)))
+       if (copy_from_user(&kmask, umask, sizeof(sigset_t)))
                return -EFAULT;
 
-       *oldset = current->blocked;
-       set_current_blocked(set);
+       set_restore_sigmask();
+       current->saved_sigmask = current->blocked;
+       set_current_blocked(&kmask);
 
        return 0;
 }
-EXPORT_SYMBOL(set_user_sigmask);
 
 #ifdef CONFIG_COMPAT
-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)
 {
-       if (!usigmask)
-               return 0;
+       sigset_t kmask;
 
+       if (!umask)
+               return 0;
        if (sigsetsize != sizeof(compat_sigset_t))
                return -EINVAL;
-       if (get_compat_sigset(set, usigmask))
+       if (get_compat_sigset(&kmask, umask))
                return -EFAULT;
 
-       *oldset = current->blocked;
-       set_current_blocked(set);
+       set_restore_sigmask();
+       current->saved_sigmask = current->blocked;
+       set_current_blocked(&kmask);
 
        return 0;
 }
-EXPORT_SYMBOL(set_compat_user_sigmask);
 #endif
 
-/*
- * restore_user_sigmask:
- * usigmask: sigmask passed in from userland.
- * sigsaved: saved sigmask when the syscall started and changed the sigmask to
- *           usigmask.
- *
- * This is useful for syscalls such as ppoll, pselect, io_pgetevents and
- * epoll_pwait where a new sigmask is passed in from userland for the syscalls.
- */
-void restore_user_sigmask(const void __user *usigmask, sigset_t *sigsaved,
-                               bool interrupted)
-{
-
-       if (!usigmask)
-               return;
-       /*
-        * When signals are pending, do not restore them here.
-        * Restoring sigmask here can lead to delivering signals that the above
-        * syscalls are intended to block because of the sigmask passed in.
-        */
-       if (interrupted) {
-               current->saved_sigmask = *sigsaved;
-               set_restore_sigmask();
-               return;
-       }
-
-       /*
-        * This is needed because the fast syscall return path does not restore
-        * saved_sigmask when signals are not pending.
-        */
-       set_current_blocked(sigsaved);
-}
-EXPORT_SYMBOL(restore_user_sigmask);
-
 /**
  *  sys_rt_sigprocmask - change the list of currently blocked signals
  *  @how: whether to add, remove, or set signals