Merge branch 'akpm' (patches from Andrew)

Merge updates from Andrew Morton:
 "Incoming:

   - a small number of updates to scripts/, ocfs2 and fs/buffer.c

   - most of MM

  I still have quite a lot of material (mostly not MM) staged after
  linux-next due to -next dependencies. I'll send those across next week
  as the preprequisites get merged up"

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (135 commits)
  mm/page_io.c: annotate refault stalls from swap_readpage
  mm/Kconfig: fix trivial help text punctuation
  mm/Kconfig: fix indentation
  mm/memory_hotplug.c: remove __online_page_set_limits()
  mm: fix typos in comments when calling __SetPageUptodate()
  mm: fix struct member name in function comments
  mm/shmem.c: cast the type of unmap_start to u64
  mm: shmem: use proper gfp flags for shmem_writepage()
  mm/shmem.c: make array 'values' static const, makes object smaller
  userfaultfd: require CAP_SYS_PTRACE for UFFD_FEATURE_EVENT_FORK
  fs/userfaultfd.c: wp: clear VM_UFFD_MISSING or VM_UFFD_WP during userfaultfd_register()
  userfaultfd: wrap the common dst_vma check into an inlined function
  userfaultfd: remove unnecessary WARN_ON() in __mcopy_atomic_hugetlb()
  userfaultfd: use vma_pagesize for all huge page size calculation
  mm/madvise.c: use PAGE_ALIGN[ED] for range checking
  mm/madvise.c: replace with page_size() in madvise_inject_error()
  mm/mmap.c: make vma_merge() comment more easy to understand
  mm/hwpoison-inject: use DEFINE_DEBUGFS_ATTRIBUTE to define debugfs fops
  autonuma: reduce cache footprint when scanning page tables
  autonuma: fix watermark checking in migrate_balanced_pgdat()
  ...

1 files changed, 29 insertions, 11 deletions

diff --git a/lib/vsprintf.c b/lib/vsprintf.c
index dee8fc467fcf..7c488a1ce318 100644
--- a/lib/vsprintf.c
+++ b/lib/vsprintf.c
@@ -761,11 +761,38 @@ static int __init initialize_ptr_random(void)
 early_initcall(initialize_ptr_random);
 
 /* Maps a pointer to a 32 bit unique identifier. */
+static inline int __ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
+{
+	unsigned long hashval;
+
+	if (static_branch_unlikely(&not_filled_random_ptr_key))
+		return -EAGAIN;
+
+#ifdef CONFIG_64BIT
+	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
+	/*
+	 * Mask off the first 32 bits, this makes explicit that we have
+	 * modified the address (and 32 bits is plenty for a unique ID).
+	 */
+	hashval = hashval & 0xffffffff;
+#else
+	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
+#endif
+	*hashval_out = hashval;
+	return 0;
+}
+
+int ptr_to_hashval(const void *ptr, unsigned long *hashval_out)
+{
+	return __ptr_to_hashval(ptr, hashval_out);
+}
+
 static char *ptr_to_id(char *buf, char *end, const void *ptr,
 		       struct printf_spec spec)
 {
 	const char *str = sizeof(ptr) == 8 ? "(____ptrval____)" : "(ptrval)";
 	unsigned long hashval;
+	int ret;
 
 	/* When debugging early boot use non-cryptographically secure hash. */
 	if (unlikely(debug_boot_weak_hash)) {
@@ -773,22 +800,13 @@ static char *ptr_to_id(char *buf, char *end, const void *ptr,
 		return pointer_string(buf, end, (const void *)hashval, spec);
 	}
 
-	if (static_branch_unlikely(&not_filled_random_ptr_key)) {
+	ret = __ptr_to_hashval(ptr, &hashval);
+	if (ret) {
 		spec.field_width = 2 * sizeof(ptr);
 		/* string length must be less than default_width */
 		return error_string(buf, end, str, spec);
 	}
 
-#ifdef CONFIG_64BIT
-	hashval = (unsigned long)siphash_1u64((u64)ptr, &ptr_key);
-	/*
-	 * Mask off the first 32 bits, this makes explicit that we have
-	 * modified the address (and 32 bits is plenty for a unique ID).
-	 */
-	hashval = hashval & 0xffffffff;
-#else
-	hashval = (unsigned long)siphash_1u32((u32)ptr, &ptr_key);
-#endif
 	return pointer_string(buf, end, (const void *)hashval, spec);
 }