Merge branch 'akpm' (patches from Andrew Morton)

Merge more patches from Andrew Morton:
 "The rest of MM.  Plus one misc cleanup"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (35 commits)
  mm/Kconfig: add MMU dependency for MIGRATION.
  kernel: replace strict_strto*() with kstrto*()
  mm, thp: count thp_fault_fallback anytime thp fault fails
  thp: consolidate code between handle_mm_fault() and do_huge_pmd_anonymous_page()
  thp: do_huge_pmd_anonymous_page() cleanup
  thp: move maybe_pmd_mkwrite() out of mk_huge_pmd()
  mm: cleanup add_to_page_cache_locked()
  thp: account anon transparent huge pages into NR_ANON_PAGES
  truncate: drop 'oldsize' truncate_pagecache() parameter
  mm: make lru_add_drain_all() selective
  memcg: document cgroup dirty/writeback memory statistics
  memcg: add per cgroup writeback pages accounting
  memcg: check for proper lock held in mem_cgroup_update_page_stat
  memcg: remove MEMCG_NR_FILE_MAPPED
  memcg: reduce function dereference
  memcg: avoid overflow caused by PAGE_ALIGN
  memcg: rename RESOURCE_MAX to RES_COUNTER_MAX
  memcg: correct RESOURCE_MAX to ULLONG_MAX
  mm: memcg: do not trap chargers with full callstack on OOM
  mm: memcg: rework and document OOM waiting and wakeup
  ...

1 files changed, 22 insertions, 21 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index 654be4ae3047..3aaeffcfd67a 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -842,23 +842,15 @@ do_sigbus(struct pt_regs *regs, unsigned long error_code, unsigned long address,
         force_sig_info_fault(SIGBUS, code, address, tsk, fault);
 }
 
-static noinline int
+static noinline void
 mm_fault_error(struct pt_regs *regs, unsigned long error_code,
                unsigned long address, unsigned int fault)
 {
-        /*
-         * Pagefault was interrupted by SIGKILL. We have no reason to
-         * continue pagefault.
-         */
-        if (fatal_signal_pending(current)) {
-                if (!(fault & VM_FAULT_RETRY))
-                        up_read(&current->mm->mmap_sem);
-                if (!(error_code & PF_USER))
-                        no_context(regs, error_code, address, 0, 0);
-                return 1;
+        if (fatal_signal_pending(current) && !(error_code & PF_USER)) {
+                up_read(&current->mm->mmap_sem);
+                no_context(regs, error_code, address, 0, 0);
+                return;
         }
-        if (!(fault & VM_FAULT_ERROR))
-                return 0;
 
         if (fault & VM_FAULT_OOM) {
                 /* Kernel mode? Handle exceptions or die: */
@@ -866,7 +858,7 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
                         up_read(&current->mm->mmap_sem);
                         no_context(regs, error_code, address,
                                    SIGSEGV, SEGV_MAPERR);
-                        return 1;
+                        return;
                 }
 
                 up_read(&current->mm->mmap_sem);
@@ -884,7 +876,6 @@ mm_fault_error(struct pt_regs *regs, unsigned long error_code,
                 else
                         BUG();
         }
-        return 1;
 }
 
 static int spurious_fault_check(unsigned long error_code, pte_t *pte)
@@ -1011,9 +1002,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
         unsigned long address;
         struct mm_struct *mm;
         int fault;
-        int write = error_code & PF_WRITE;
-        unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE |
-                                        (write ? FAULT_FLAG_WRITE : 0);
+        unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
 
         tsk = current;
         mm = tsk->mm;
@@ -1083,6 +1072,7 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
         if (user_mode_vm(regs)) {
                 local_irq_enable();
                 error_code |= PF_USER;
+                flags |= FAULT_FLAG_USER;
         } else {
                 if (regs->flags & X86_EFLAGS_IF)
                         local_irq_enable();
@@ -1109,6 +1099,9 @@ __do_page_fault(struct pt_regs *regs, unsigned long error_code)
                 return;
         }
 
+        if (error_code & PF_WRITE)
+                flags |= FAULT_FLAG_WRITE;
+
         /*
          * When running in the kernel we expect faults to occur only to
          * addresses in user space.  All other faults represent errors in
@@ -1187,9 +1180,17 @@ good_area:
          */
         fault = handle_mm_fault(mm, vma, address, flags);
 
-        if (unlikely(fault & (VM_FAULT_RETRY|VM_FAULT_ERROR))) {
-                if (mm_fault_error(regs, error_code, address, fault))
-                        return;
+        /*
+         * If we need to retry but a fatal signal is pending, handle the
+         * signal first. We do not need to release the mmap_sem because it
+         * would already be released in __lock_page_or_retry in mm/filemap.c.
+         */
+        if (unlikely((fault & VM_FAULT_RETRY) && fatal_signal_pending(current)))
+                return;
+
+        if (unlikely(fault & VM_FAULT_ERROR)) {
+                mm_fault_error(regs, error_code, address, fault);
+                return;
         }
 
         /*