Merge branch 'akpm' (patches from Andrew)

Merge more updates from Andrew Morton:
 "VM:
   - z3fold fixes and enhancements by Henry Burns and Vitaly Wool

   - more accurate reclaimed slab caches calculations by Yafang Shao

   - fix MAP_UNINITIALIZED UAPI symbol to not depend on config, by
     Christoph Hellwig

   - !CONFIG_MMU fixes by Christoph Hellwig

   - new novmcoredd parameter to omit device dumps from vmcore, by
     Kairui Song

   - new test_meminit module for testing heap and pagealloc
     initialization, by Alexander Potapenko

   - ioremap improvements for huge mappings, by Anshuman Khandual

   - generalize kprobe page fault handling, by Anshuman Khandual

   - device-dax hotplug fixes and improvements, by Pavel Tatashin

   - enable synchronous DAX fault on powerpc, by Aneesh Kumar K.V

   - add pte_devmap() support for arm64, by Robin Murphy

   - unify locked_vm accounting with a helper, by Daniel Jordan

   - several misc fixes

  core/lib:
   - new typeof_member() macro including some users, by Alexey Dobriyan

   - make BIT() and GENMASK() available in asm, by Masahiro Yamada

   - changed LIST_POISON2 on x86_64 to 0xdead000000000122 for better
     code generation, by Alexey Dobriyan

   - rbtree code size optimizations, by Michel Lespinasse

   - convert struct pid count to refcount_t, by Joel Fernandes

  get_maintainer.pl:
   - add --no-moderated switch to skip moderated ML's, by Joe Perches

  misc:
   - ptrace PTRACE_GET_SYSCALL_INFO interface

   - coda updates

   - gdb scripts, various"

[ Using merge message suggestion from Vlastimil Babka, with some editing - Linus ]

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (100 commits)
  fs/select.c: use struct_size() in kmalloc()
  mm: add account_locked_vm utility function
  arm64: mm: implement pte_devmap support
  mm: introduce ARCH_HAS_PTE_DEVMAP
  mm: clean up is_device_*_page() definitions
  mm/mmap: move common defines to mman-common.h
  mm: move MAP_SYNC to asm-generic/mman-common.h
  device-dax: "Hotremove" persistent memory that is used like normal RAM
  mm/hotplug: make remove_memory() interface usable
  device-dax: fix memory and resource leak if hotplug fails
  include/linux/lz4.h: fix spelling and copy-paste errors in documentation
  ipc/mqueue.c: only perform resource calculation if user valid
  include/asm-generic/bug.h: fix "cut here" for WARN_ON for __WARN_TAINT architectures
  scripts/gdb: add helpers to find and list devices
  scripts/gdb: add lx-genpd-summary command
  drivers/pps/pps.c: clear offset flags in PPS_SETPARAMS ioctl
  kernel/pid.c: convert struct pid count to refcount_t
  drivers/rapidio/devices/rio_mport_cdev.c: NUL terminate some strings
  select: shift restore_saved_sigmask_unless() into poll_select_copy_remaining()
  select: change do_poll() to return -ERESTARTNOHAND rather than -EINTR
  ...

1 files changed, 19 insertions, 50 deletions

diff --git a/kernel/signal.c b/kernel/signal.c
index dabe100d2091..91b789dd6e72 100644
--- 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