Merge branch 'akpm' (patches from Andrew)

Merge even more updates from Andrew Morton:

 - a kernel-wide sweep of show_stack()

 - pagetable cleanups

 - abstract out accesses to mmap_sem - prep for mmap_sem scalability work

 - hch's user acess work

Subsystems affected by this patch series: debug, mm/pagemap, mm/maccess,
mm/documentation.

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (93 commits)
  include/linux/cache.h: expand documentation over __read_mostly
  maccess: return -ERANGE when probe_kernel_read() fails
  x86: use non-set_fs based maccess routines
  maccess: allow architectures to provide kernel probing directly
  maccess: move user access routines together
  maccess: always use strict semantics for probe_kernel_read
  maccess: remove strncpy_from_unsafe
  tracing/kprobes: handle mixed kernel/userspace probes better
  bpf: rework the compat kernel probe handling
  bpf:bpf_seq_printf(): handle potentially unsafe format string better
  bpf: handle the compat string in bpf_trace_copy_string better
  bpf: factor out a bpf_trace_copy_string helper
  maccess: unify the probe kernel arch hooks
  maccess: remove probe_read_common and probe_write_common
  maccess: rename strnlen_unsafe_user to strnlen_user_nofault
  maccess: rename strncpy_from_unsafe_strict to strncpy_from_kernel_nofault
  maccess: rename strncpy_from_unsafe_user to strncpy_from_user_nofault
  maccess: update the top of file comment
  maccess: clarify kerneldoc comments
  maccess: remove duplicate kerneldoc comments
  ...

22 files changed, 1583 insertions, 88 deletions

diff --git a/include/linux/cache.h b/include/linux/cache.h
index 750621e41d1c..1aa8009f6d06 100644
--- a/include/linux/cache.h
+++ b/include/linux/cache.h
@@ -15,8 +15,14 @@
 
 /*
  * __read_mostly is used to keep rarely changing variables out of frequently
- * updated cachelines. If an architecture doesn't support it, ignore the
- * hint.
+ * updated cachelines. Its use should be reserved for data that is used
+ * frequently in hot paths. Performance traces can help decide when to use
+ * this. You want __read_mostly data to be tightly packed, so that in the
+ * best case multiple frequently read variables for a hot path will be next
+ * to each other in order to reduce the number of cachelines needed to
+ * execute a critical path. We should be mindful and selective of its use.
+ * ie: if you're going to use it please supply a *good* justification in your
+ * commit log
  */
 #ifndef __read_mostly
 #define __read_mostly
diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h
index bc156285d097..a5192b718dbe 100644
--- a/include/linux/crash_dump.h
+++ b/include/linux/crash_dump.h
@@ -5,9 +5,10 @@
 #include <linux/kexec.h>
 #include <linux/proc_fs.h>
 #include <linux/elf.h>
+#include <linux/pgtable.h>
 #include <uapi/linux/vmcore.h>
 
-#include <asm/pgtable.h> /* for pgprot_t */
+#include <linux/pgtable.h> /* for pgprot_t */
 
 #ifdef CONFIG_CRASH_DUMP
 #define ELFCORE_ADDR_MAX	(-1ULL)
diff --git a/include/linux/dax.h b/include/linux/dax.h
index d7af5d243f24..6904d4e0b2e0 100644
--- a/include/linux/dax.h
+++ b/include/linux/dax.h
@@ -5,7 +5,6 @@
 #include <linux/fs.h>
 #include <linux/mm.h>
 #include <linux/radix-tree.h>
-#include <asm/pgtable.h>
 
 /* Flag for synchronous flush */
 #define DAXDEV_F_SYNC (1UL << 0)
diff --git a/include/linux/dma-noncoherent.h b/include/linux/dma-noncoherent.h
index b59f1b6be3e9..ca09a4e07d2d 100644
--- a/include/linux/dma-noncoherent.h
+++ b/include/linux/dma-noncoherent.h
@@ -3,7 +3,7 @@
 #define _LINUX_DMA_NONCOHERENT_H 1
 
 #include <linux/dma-mapping.h>
-#include <asm/pgtable.h>
+#include <linux/pgtable.h>
 
 #ifdef CONFIG_ARCH_HAS_DMA_COHERENCE_H
 #include <asm/dma-coherence.h>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 01f5d296f9bb..0b026329dbed 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1679,10 +1679,10 @@ static inline int sb_start_write_trylock(struct super_block *sb)
  *
  * Since page fault freeze protection behaves as a lock, users have to preserve
  * ordering of freeze protection and other filesystem locks. It is advised to
- * put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault
+ * put sb_start_pagefault() close to mmap_lock in lock ordering. Page fault
  * handling code implies lock dependency:
  *
- * mmap_sem
+ * mmap_lock
  *   -> sb_start_pagefault
  */
 static inline void sb_start_pagefault(struct super_block *sb)
diff --git a/include/linux/hmm.h b/include/linux/hmm.h
index e912b9dc4633..f4a09ed223ac 100644
--- a/include/linux/hmm.h
+++ b/include/linux/hmm.h
@@ -10,7 +10,7 @@
 #define LINUX_HMM_H
 
 #include <linux/kconfig.h>
-#include <asm/pgtable.h>
+#include <linux/pgtable.h>
 
 #include <linux/device.h>
 #include <linux/migrate.h>
diff --git a/include/linux/huge_mm.h b/include/linux/huge_mm.h
index cfbb0a87c5f0..71f20776b06c 100644
--- a/include/linux/huge_mm.h
+++ b/include/linux/huge_mm.h
@@ -248,7 +248,7 @@ static inline int is_swap_pmd(pmd_t pmd)
 	return !pmd_none(pmd) && !pmd_present(pmd);
 }
 
-/* mmap_sem must be held on entry */
+/* mmap_lock must be held on entry */
 static inline spinlock_t *pmd_trans_huge_lock(pmd_t *pmd,
 		struct vm_area_struct *vma)
 {
diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
index 0cced410e0bd..50650d0d01b9 100644
--- a/include/linux/hugetlb.h
+++ b/include/linux/hugetlb.h
@@ -9,7 +9,7 @@
 #include <linux/cgroup.h>
 #include <linux/list.h>
 #include <linux/kref.h>
-#include <asm/pgtable.h>
+#include <linux/pgtable.h>
 
 struct ctl_table;
 struct user_struct;
diff --git a/include/linux/io-mapping.h b/include/linux/io-mapping.h
index b336622612f3..0beaa3eba155 100644
--- a/include/linux/io-mapping.h
+++ b/include/linux/io-mapping.h
@@ -10,6 +10,7 @@
 #include <linux/slab.h>
 #include <linux/bug.h>
 #include <linux/io.h>
+#include <linux/pgtable.h>
 #include <asm/page.h>
 
 /*
@@ -99,7 +100,6 @@ io_mapping_unmap(void __iomem *vaddr)
 #else
 
 #include <linux/uaccess.h>
-#include <asm/pgtable.h>
 
 /* Create the io_mapping object*/
 static inline struct io_mapping *
diff --git a/include/linux/kallsyms.h b/include/linux/kallsyms.h
index 657a83b943f0..98338dc6b5d2 100644
--- a/include/linux/kallsyms.h
+++ b/include/linux/kallsyms.h
@@ -165,9 +165,9 @@ static inline int kallsyms_show_value(void)
 
 #endif /*CONFIG_KALLSYMS*/
 
-static inline void print_ip_sym(unsigned long ip)
+static inline void print_ip_sym(const char *loglvl, unsigned long ip)
 {
-	printk("[<%px>] %pS\n", (void *) ip, (void *) ip);
+	printk("%s[<%px>] %pS\n", loglvl, (void *) ip, (void *) ip);
 }
 
 #endif /*_LINUX_KALLSYMS_H*/
diff --git a/include/linux/kasan.h b/include/linux/kasan.h
index 31314ca7c635..82522e996c76 100644
--- a/include/linux/kasan.h
+++ b/include/linux/kasan.h
@@ -11,8 +11,8 @@ struct task_struct;
 
 #ifdef CONFIG_KASAN
 
+#include <linux/pgtable.h>
 #include <asm/kasan.h>
-#include <asm/pgtable.h>
 
 extern unsigned char kasan_early_shadow_page[PAGE_SIZE];
 extern pte_t kasan_early_shadow_pte[PTRS_PER_PTE];
diff --git a/include/linux/mempolicy.h b/include/linux/mempolicy.h
index 8165278c348a..ea9c15b60a96 100644
--- a/include/linux/mempolicy.h
+++ b/include/linux/mempolicy.h
@@ -31,7 +31,7 @@ struct mm_struct;
  * Locking policy for interlave:
  * In process context there is no locking because only the process accesses
  * its own state. All vma manipulation is somewhat protected by a down_read on
- * mmap_sem.
+ * mmap_lock.
  *
  * Freeing policy:
  * Mempolicy objects are reference counted.  A mempolicy will be freed when
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 9d6042178ca7..dc7b87310c10 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -15,6 +15,7 @@
 #include <linux/atomic.h>
 #include <linux/debug_locks.h>
 #include <linux/mm_types.h>
+#include <linux/mmap_lock.h>
 #include <linux/range.h>
 #include <linux/pfn.h>
 #include <linux/percpu-refcount.h>
@@ -28,6 +29,7 @@
 #include <linux/overflow.h>
 #include <linux/sizes.h>
 #include <linux/sched.h>
+#include <linux/pgtable.h>
 
 struct mempolicy;
 struct anon_vma;
@@ -92,7 +94,6 @@ extern int mmap_rnd_compat_bits __read_mostly;
 #endif
 
 #include <asm/page.h>
-#include <asm/pgtable.h>
 #include <asm/processor.h>
 
 /*
@@ -401,7 +402,7 @@ extern pgprot_t protection_map[16];
  * @FAULT_FLAG_WRITE: Fault was a write fault.
  * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE.
  * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked.
- * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_sem and wait when retrying.
+ * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying.
  * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region.
  * @FAULT_FLAG_TRIED: The fault has been tried once.
  * @FAULT_FLAG_USER: The fault originated in userspace.
@@ -451,10 +452,10 @@ extern pgprot_t protection_map[16];
  * fault_flag_allow_retry_first - check ALLOW_RETRY the first time
  *
  * This is mostly used for places where we want to try to avoid taking
- * the mmap_sem for too long a time when waiting for another condition
+ * the mmap_lock for too long a time when waiting for another condition
  * to change, in which case we can try to be polite to release the
- * mmap_sem in the first round to avoid potential starvation of other
- * processes that would also want the mmap_sem.
+ * mmap_lock in the first round to avoid potential starvation of other
+ * processes that would also want the mmap_lock.
  *
  * Return: true if the page fault allows retry and this is the first
  * attempt of the fault handling; false otherwise.
@@ -581,7 +582,7 @@ struct vm_operations_struct {
 	 * (vma,addr) marked as MPOL_SHARED.  The shared policy infrastructure
 	 * in mm/mempolicy.c will do this automatically.
 	 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
-	 * marked as MPOL_SHARED. vma policies are protected by the mmap_sem.
+	 * marked as MPOL_SHARED. vma policies are protected by the mmap_lock.
 	 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
 	 * must return NULL--i.e., do not "fallback" to task or system default
 	 * policy.
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
index ef6d3aface8a..64ede5f150dc 100644
--- a/include/linux/mm_types.h
+++ b/include/linux/mm_types.h
@@ -344,7 +344,7 @@ struct vm_area_struct {
 	 * can only be in the i_mmap tree.  An anonymous MAP_PRIVATE, stack
 	 * or brk vma (with NULL file) can only be in an anon_vma list.
 	 */
-	struct list_head anon_vma_chain; /* Serialized by mmap_sem &
+	struct list_head anon_vma_chain; /* Serialized by mmap_lock &
 					  * page_table_lock */
 	struct anon_vma *anon_vma;	/* Serialized by page_table_lock */
 
@@ -440,7 +440,7 @@ struct mm_struct {
 		spinlock_t page_table_lock; /* Protects page tables and some
 					     * counters
 					     */
-		struct rw_semaphore mmap_sem;
+		struct rw_semaphore mmap_lock;
 
 		struct list_head mmlist; /* List of maybe swapped mm's.	These
 					  * are globally strung together off
diff --git a/include/linux/mmap_lock.h b/include/linux/mmap_lock.h
new file mode 100644
index 000000000000..0707671851a8
--- /dev/null
+++ b/include/linux/mmap_lock.h
@@ -0,0 +1,90 @@
+#ifndef _LINUX_MMAP_LOCK_H
+#define _LINUX_MMAP_LOCK_H
+
+#include <linux/mmdebug.h>
+
+#define MMAP_LOCK_INITIALIZER(name) \
+	.mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
+
+static inline void mmap_init_lock(struct mm_struct *mm)
+{
+	init_rwsem(&mm->mmap_lock);
+}
+
+static inline void mmap_write_lock(struct mm_struct *mm)
+{
+	down_write(&mm->mmap_lock);
+}
+
+static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
+{
+	down_write_nested(&mm->mmap_lock, subclass);
+}
+
+static inline int mmap_write_lock_killable(struct mm_struct *mm)
+{
+	return down_write_killable(&mm->mmap_lock);
+}
+
+static inline bool mmap_write_trylock(struct mm_struct *mm)
+{
+	return down_write_trylock(&mm->mmap_lock) != 0;
+}
+
+static inline void mmap_write_unlock(struct mm_struct *mm)
+{
+	up_write(&mm->mmap_lock);
+}
+
+static inline void mmap_write_downgrade(struct mm_struct *mm)
+{
+	downgrade_write(&mm->mmap_lock);
+}
+
+static inline void mmap_read_lock(struct mm_struct *mm)
+{
+	down_read(&mm->mmap_lock);
+}
+
+static inline int mmap_read_lock_killable(struct mm_struct *mm)
+{
+	return down_read_killable(&mm->mmap_lock);
+}
+
+static inline bool mmap_read_trylock(struct mm_struct *mm)
+{
+	return down_read_trylock(&mm->mmap_lock) != 0;
+}
+
+static inline void mmap_read_unlock(struct mm_struct *mm)
+{
+	up_read(&mm->mmap_lock);
+}
+
+static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
+{
+	if (down_read_trylock(&mm->mmap_lock)) {
+		rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
+		return true;
+	}
+	return false;
+}
+
+static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
+{
+	up_read_non_owner(&mm->mmap_lock);
+}
+
+static inline void mmap_assert_locked(struct mm_struct *mm)
+{
+	lockdep_assert_held(&mm->mmap_lock);
+	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+}
+
+static inline void mmap_assert_write_locked(struct mm_struct *mm)
+{
+	lockdep_assert_held_write(&mm->mmap_lock);
+	VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
+}
+
+#endif /* _LINUX_MMAP_LOCK_H */
diff --git a/include/linux/mmu_notifier.h b/include/linux/mmu_notifier.h
index 736f6918335e..fc68f3570e19 100644
--- a/include/linux/mmu_notifier.h
+++ b/include/linux/mmu_notifier.h
@@ -5,6 +5,7 @@
 #include <linux/list.h>
 #include <linux/spinlock.h>
 #include <linux/mm_types.h>
+#include <linux/mmap_lock.h>
 #include <linux/srcu.h>
 #include <linux/interval_tree.h>
 
@@ -121,7 +122,7 @@ struct mmu_notifier_ops {
 
 	/*
 	 * invalidate_range_start() and invalidate_range_end() must be
-	 * paired and are called only when the mmap_sem and/or the
+	 * paired and are called only when the mmap_lock and/or the
 	 * locks protecting the reverse maps are held. If the subsystem
 	 * can't guarantee that no additional references are taken to
 	 * the pages in the range, it has to implement the
@@ -212,13 +213,13 @@ struct mmu_notifier_ops {
 };
 
 /*
- * The notifier chains are protected by mmap_sem and/or the reverse map
+ * The notifier chains are protected by mmap_lock and/or the reverse map
  * semaphores. Notifier chains are only changed when all reverse maps and
- * the mmap_sem locks are taken.
+ * the mmap_lock locks are taken.
  *
  * Therefore notifier chains can only be traversed when either
  *
- * 1. mmap_sem is held.
+ * 1. mmap_lock is held.
  * 2. One of the reverse map locks is held (i_mmap_rwsem or anon_vma->rwsem).
  * 3. No other concurrent thread can access the list (release)
  */
@@ -277,9 +278,9 @@ mmu_notifier_get(const struct mmu_notifier_ops *ops, struct mm_struct *mm)
 {
 	struct mmu_notifier *ret;
 
-	down_write(&mm->mmap_sem);
+	mmap_write_lock(mm);
 	ret = mmu_notifier_get_locked(ops, mm);
-	up_write(&mm->mmap_sem);
+	mmap_write_unlock(mm);
 	return ret;
 }
 void mmu_notifier_put(struct mmu_notifier *subscription);
diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 8e085713150c..cf2468da68e9 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -538,7 +538,7 @@ static inline int lock_page_killable(struct page *page)
  * lock_page_or_retry - Lock the page, unless this would block and the
  * caller indicated that it can handle a retry.
  *
- * Return value and mmap_sem implications depend on flags; see
+ * Return value and mmap_lock implications depend on flags; see
  * __lock_page_or_retry().
  */
 static inline int lock_page_or_retry(struct page *page, struct mm_struct *mm,
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
new file mode 100644
index 000000000000..32b6c52d41b9
--- /dev/null
+++ b/include/linux/pgtable.h
@@ -0,0 +1,1438 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_PGTABLE_H
+#define _LINUX_PGTABLE_H
+
+#include <linux/pfn.h>
+#include <asm/pgtable.h>
+
+#ifndef __ASSEMBLY__
+#ifdef CONFIG_MMU
+
+#include <linux/mm_types.h>
+#include <linux/bug.h>
+#include <linux/errno.h>
+#include <asm-generic/pgtable_uffd.h>
+
+#if 5 - defined(__PAGETABLE_P4D_FOLDED) - defined(__PAGETABLE_PUD_FOLDED) - \
+	defined(__PAGETABLE_PMD_FOLDED) != CONFIG_PGTABLE_LEVELS
+#error CONFIG_PGTABLE_LEVELS is not consistent with __PAGETABLE_{P4D,PUD,PMD}_FOLDED
+#endif
+
+/*
+ * On almost all architectures and configurations, 0 can be used as the
+ * upper ceiling to free_pgtables(): on many architectures it has the same
+ * effect as using TASK_SIZE.  However, there is one configuration which
+ * must impose a more careful limit, to avoid freeing kernel pgtables.
+ */
+#ifndef USER_PGTABLES_CEILING
+#define USER_PGTABLES_CEILING	0UL
+#endif
+
+/*
+ * A page table page can be thought of an array like this: pXd_t[PTRS_PER_PxD]
+ *
+ * The pXx_index() functions return the index of the entry in the page
+ * table page which would control the given virtual address
+ *
+ * As these functions may be used by the same code for different levels of
+ * the page table folding, they are always available, regardless of
+ * CONFIG_PGTABLE_LEVELS value. For the folded levels they simply return 0
+ * because in such cases PTRS_PER_PxD equals 1.
+ */
+
+static inline unsigned long pte_index(unsigned long address)
+{
+	return (address >> PAGE_SHIFT) & (PTRS_PER_PTE - 1);
+}
+
+#ifndef pmd_index
+static inline unsigned long pmd_index(unsigned long address)
+{
+	return (address >> PMD_SHIFT) & (PTRS_PER_PMD - 1);
+}
+#define pmd_index pmd_index
+#endif
+
+#ifndef pud_index
+static inline unsigned long pud_index(unsigned long address)
+{
+	return (address >> PUD_SHIFT) & (PTRS_PER_PUD - 1);
+}
+#define pud_index pud_index
+#endif
+
+#ifndef pgd_index
+/* Must be a compile-time constant, so implement it as a macro */
+#define pgd_index(a)  (((a) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
+#endif
+
+#ifndef pte_offset_kernel
+static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long address)
+{
+	return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(address);
+}
+#define pte_offset_kernel pte_offset_kernel
+#endif
+
+#if defined(CONFIG_HIGHPTE)
+#define pte_offset_map(dir, address)				\
+	((pte_t *)kmap_atomic(pmd_page(*(dir))) +		\
+	 pte_index((address)))
+#define pte_unmap(pte) kunmap_atomic((pte))
+#else
+#define pte_offset_map(dir, address)	pte_offset_kernel((dir), (address))
+#define pte_unmap(pte) ((void)(pte))	/* NOP */
+#endif
+
+/* Find an entry in the second-level page table.. */
+#ifndef pmd_offset
+static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address)
+{
+	return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(address);
+}
+#define pmd_offset pmd_offset
+#endif
+
+#ifndef pud_offset
+static inline pud_t *pud_offset(p4d_t *p4d, unsigned long address)
+{
+	return (pud_t *)p4d_page_vaddr(*p4d) + pud_index(address);
+}
+#define pud_offset pud_offset
+#endif
+
+static inline pgd_t *pgd_offset_pgd(pgd_t *pgd, unsigned long address)
+{
+	return (pgd + pgd_index(address));
+};
+
+/*
+ * a shortcut to get a pgd_t in a given mm
+ */
+#ifndef pgd_offset
+#define pgd_offset(mm, address)		pgd_offset_pgd((mm)->pgd, (address))
+#endif
+
+/*
+ * a shortcut which implies the use of the kernel's pgd, instead
+ * of a process's
+ */
+#define pgd_offset_k(address)		pgd_offset(&init_mm, (address))
+
+/*
+ * In many cases it is known that a virtual address is mapped at PMD or PTE
+ * level, so instead of traversing all the page table levels, we can get a
+ * pointer to the PMD entry in user or kernel page table or translate a virtual
+ * address to the pointer in the PTE in the kernel page tables with simple
+ * helpers.
+ */
+static inline pmd_t *pmd_off(struct mm_struct *mm, unsigned long va)
+{
+	return pmd_offset(pud_offset(p4d_offset(pgd_offset(mm, va), va), va), va);
+}
+
+static inline pmd_t *pmd_off_k(unsigned long va)
+{
+	return pmd_offset(pud_offset(p4d_offset(pgd_offset_k(va), va), va), va);
+}
+
+static inline pte_t *virt_to_kpte(unsigned long vaddr)
+{
+	pmd_t *pmd = pmd_off_k(vaddr);
+
+	return pmd_none(*pmd) ? NULL : pte_offset_kernel(pmd, vaddr);
+}
+
+#ifndef __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
+extern int ptep_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pte_t *ptep,
+				 pte_t entry, int dirty);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SET_ACCESS_FLAGS
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern int pmdp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp,
+				 pmd_t entry, int dirty);
+extern int pudp_set_access_flags(struct vm_area_struct *vma,
+				 unsigned long address, pud_t *pudp,
+				 pud_t entry, int dirty);
+#else
+static inline int pmdp_set_access_flags(struct vm_area_struct *vma,
+					unsigned long address, pmd_t *pmdp,
+					pmd_t entry, int dirty)
+{
+	BUILD_BUG();
+	return 0;
+}
+static inline int pudp_set_access_flags(struct vm_area_struct *vma,
+					unsigned long address, pud_t *pudp,
+					pud_t entry, int dirty)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pte_t *ptep)
+{
+	pte_t pte = *ptep;
+	int r = 1;
+	if (!pte_young(pte))
+		r = 0;
+	else
+		set_pte_at(vma->vm_mm, address, ptep, pte_mkold(pte));
+	return r;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_TEST_AND_CLEAR_YOUNG
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pmd_t *pmdp)
+{
+	pmd_t pmd = *pmdp;
+	int r = 1;
+	if (!pmd_young(pmd))
+		r = 0;
+	else
+		set_pmd_at(vma->vm_mm, address, pmdp, pmd_mkold(pmd));
+	return r;
+}
+#else
+static inline int pmdp_test_and_clear_young(struct vm_area_struct *vma,
+					    unsigned long address,
+					    pmd_t *pmdp)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
+int ptep_clear_flush_young(struct vm_area_struct *vma,
+			   unsigned long address, pte_t *ptep);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_CLEAR_YOUNG_FLUSH
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern int pmdp_clear_flush_young(struct vm_area_struct *vma,
+				  unsigned long address, pmd_t *pmdp);
+#else
+/*
+ * Despite relevant to THP only, this API is called from generic rmap code
+ * under PageTransHuge(), hence needs a dummy implementation for !THP
+ */
+static inline int pmdp_clear_flush_young(struct vm_area_struct *vma,
+					 unsigned long address, pmd_t *pmdp)
+{
+	BUILD_BUG();
+	return 0;
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR
+static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
+				       unsigned long address,
+				       pte_t *ptep)
+{
+	pte_t pte = *ptep;
+	pte_clear(mm, address, ptep);
+	return pte;
+}
+#endif
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
+static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address,
+					    pmd_t *pmdp)
+{
+	pmd_t pmd = *pmdp;
+	pmd_clear(pmdp);
+	return pmd;
+}
+#endif /* __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR */
+#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR
+static inline pud_t pudp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address,
+					    pud_t *pudp)
+{
+	pud_t pud = *pudp;
+
+	pud_clear(pudp);
+	return pud;
+}
+#endif /* __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#ifndef __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR_FULL
+static inline pmd_t pmdp_huge_get_and_clear_full(struct vm_area_struct *vma,
+					    unsigned long address, pmd_t *pmdp,
+					    int full)
+{
+	return pmdp_huge_get_and_clear(vma->vm_mm, address, pmdp);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PUDP_HUGE_GET_AND_CLEAR_FULL
+static inline pud_t pudp_huge_get_and_clear_full(struct mm_struct *mm,
+					    unsigned long address, pud_t *pudp,
+					    int full)
+{
+	return pudp_huge_get_and_clear(mm, address, pudp);
+}
+#endif
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifndef __HAVE_ARCH_PTEP_GET_AND_CLEAR_FULL
+static inline pte_t ptep_get_and_clear_full(struct mm_struct *mm,
+					    unsigned long address, pte_t *ptep,
+					    int full)
+{
+	pte_t pte;
+	pte = ptep_get_and_clear(mm, address, ptep);
+	return pte;
+}
+#endif
+
+
+/*
+ * If two threads concurrently fault at the same page, the thread that
+ * won the race updates the PTE and its local TLB/Cache. The other thread
+ * gives up, simply does nothing, and continues; on architectures where
+ * software can update TLB,  local TLB can be updated here to avoid next page
+ * fault. This function updates TLB only, do nothing with cache or others.
+ * It is the difference with function update_mmu_cache.
+ */
+#ifndef __HAVE_ARCH_UPDATE_MMU_TLB
+static inline void update_mmu_tlb(struct vm_area_struct *vma,
+				unsigned long address, pte_t *ptep)
+{
+}
+#define __HAVE_ARCH_UPDATE_MMU_TLB
+#endif
+
+/*
+ * Some architectures may be able to avoid expensive synchronization
+ * primitives when modifications are made to PTE's which are already
+ * not present, or in the process of an address space destruction.
+ */
+#ifndef __HAVE_ARCH_PTE_CLEAR_NOT_PRESENT_FULL
+static inline void pte_clear_not_present_full(struct mm_struct *mm,
+					      unsigned long address,
+					      pte_t *ptep,
+					      int full)
+{
+	pte_clear(mm, address, ptep);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_CLEAR_FLUSH
+extern pte_t ptep_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pte_t *ptep);
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_HUGE_CLEAR_FLUSH
+extern pmd_t pmdp_huge_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pmd_t *pmdp);
+extern pud_t pudp_huge_clear_flush(struct vm_area_struct *vma,
+			      unsigned long address,
+			      pud_t *pudp);
+#endif
+
+#ifndef __HAVE_ARCH_PTEP_SET_WRPROTECT
+struct mm_struct;
+static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long address, pte_t *ptep)
+{
+	pte_t old_pte = *ptep;
+	set_pte_at(mm, address, ptep, pte_wrprotect(old_pte));
+}
+#endif
+
+/*
+ * On some architectures hardware does not set page access bit when accessing
+ * memory page, it is responsibilty of software setting this bit. It brings
+ * out extra page fault penalty to track page access bit. For optimization page
+ * access bit can be set during all page fault flow on these arches.
+ * To be differentiate with macro pte_mkyoung, this macro is used on platforms
+ * where software maintains page access bit.
+ */
+#ifndef pte_sw_mkyoung
+static inline pte_t pte_sw_mkyoung(pte_t pte)
+{
+	return pte;
+}
+#define pte_sw_mkyoung	pte_sw_mkyoung
+#endif
+
+#ifndef pte_savedwrite
+#define pte_savedwrite pte_write
+#endif
+
+#ifndef pte_mk_savedwrite
+#define pte_mk_savedwrite pte_mkwrite
+#endif
+
+#ifndef pte_clear_savedwrite
+#define pte_clear_savedwrite pte_wrprotect
+#endif
+
+#ifndef pmd_savedwrite
+#define pmd_savedwrite pmd_write
+#endif
+
+#ifndef pmd_mk_savedwrite
+#define pmd_mk_savedwrite pmd_mkwrite
+#endif
+
+#ifndef pmd_clear_savedwrite
+#define pmd_clear_savedwrite pmd_wrprotect
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_SET_WRPROTECT
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline void pmdp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pmd_t *pmdp)
+{
+	pmd_t old_pmd = *pmdp;
+	set_pmd_at(mm, address, pmdp, pmd_wrprotect(old_pmd));
+}
+#else
+static inline void pmdp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pmd_t *pmdp)
+{
+	BUILD_BUG();
+}
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+#ifndef __HAVE_ARCH_PUDP_SET_WRPROTECT
+#ifdef CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD
+static inline void pudp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pud_t *pudp)
+{
+	pud_t old_pud = *pudp;
+
+	set_pud_at(mm, address, pudp, pud_wrprotect(old_pud));
+}
+#else
+static inline void pudp_set_wrprotect(struct mm_struct *mm,
+				      unsigned long address, pud_t *pudp)
+{
+	BUILD_BUG();
+}
+#endif /* CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD */
+#endif
+
+#ifndef pmdp_collapse_flush
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+extern pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
+				 unsigned long address, pmd_t *pmdp);
+#else
+static inline pmd_t pmdp_collapse_flush(struct vm_area_struct *vma,
+					unsigned long address,
+					pmd_t *pmdp)
+{
+	BUILD_BUG();
+	return *pmdp;
+}
+#define pmdp_collapse_flush pmdp_collapse_flush
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+#endif
+
+#ifndef __HAVE_ARCH_PGTABLE_DEPOSIT
+extern void pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp,
+				       pgtable_t pgtable);
+#endif
+
+#ifndef __HAVE_ARCH_PGTABLE_WITHDRAW
+extern pgtable_t pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp);
+#endif
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * This is an implementation of pmdp_establish() that is only suitable for an
+ * architecture that doesn't have hardware dirty/accessed bits. In this case we
+ * can't race with CPU which sets these bits and non-atomic aproach is fine.
+ */
+static inline pmd_t generic_pmdp_establish(struct vm_area_struct *vma,
+		unsigned long address, pmd_t *pmdp, pmd_t pmd)
+{
+	pmd_t old_pmd = *pmdp;
+	set_pmd_at(vma->vm_mm, address, pmdp, pmd);
+	return old_pmd;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PMDP_INVALIDATE
+extern pmd_t pmdp_invalidate(struct vm_area_struct *vma, unsigned long address,
+			    pmd_t *pmdp);
+#endif
+
+#ifndef __HAVE_ARCH_PTE_SAME
+static inline int pte_same(pte_t pte_a, pte_t pte_b)
+{
+	return pte_val(pte_a) == pte_val(pte_b);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PTE_UNUSED
+/*
+ * Some architectures provide facilities to virtualization guests
+ * so that they can flag allocated pages as unused. This allows the
+ * host to transparently reclaim unused pages. This function returns
+ * whether the pte's page is unused.
+ */
+static inline int pte_unused(pte_t pte)
+{
+	return 0;
+}
+#endif
+
+#ifndef pte_access_permitted
+#define pte_access_permitted(pte, write) \
+	(pte_present(pte) && (!(write) || pte_write(pte)))
+#endif
+
+#ifndef pmd_access_permitted
+#define pmd_access_permitted(pmd, write) \
+	(pmd_present(pmd) && (!(write) || pmd_write(pmd)))
+#endif
+
+#ifndef pud_access_permitted
+#define pud_access_permitted(pud, write) \
+	(pud_present(pud) && (!(write) || pud_write(pud)))
+#endif
+
+#ifndef p4d_access_permitted
+#define p4d_access_permitted(p4d, write) \
+	(p4d_present(p4d) && (!(write) || p4d_write(p4d)))
+#endif
+
+#ifndef pgd_access_permitted
+#define pgd_access_permitted(pgd, write) \
+	(pgd_present(pgd) && (!(write) || pgd_write(pgd)))
+#endif
+
+#ifndef __HAVE_ARCH_PMD_SAME
+static inline int pmd_same(pmd_t pmd_a, pmd_t pmd_b)
+{
+	return pmd_val(pmd_a) == pmd_val(pmd_b);
+}
+
+static inline int pud_same(pud_t pud_a, pud_t pud_b)
+{
+	return pud_val(pud_a) == pud_val(pud_b);
+}
+#endif
+
+#ifndef __HAVE_ARCH_P4D_SAME
+static inline int p4d_same(p4d_t p4d_a, p4d_t p4d_b)
+{
+	return p4d_val(p4d_a) == p4d_val(p4d_b);
+}
+#endif
+
+#ifndef __HAVE_ARCH_PGD_SAME
+static inline int pgd_same(pgd_t pgd_a, pgd_t pgd_b)
+{
+	return pgd_val(pgd_a) == pgd_val(pgd_b);
+}
+#endif
+
+/*
+ * Use set_p*_safe(), and elide TLB flushing, when confident that *no*
+ * TLB flush will be required as a result of the "set". For example, use
+ * in scenarios where it is known ahead of time that the routine is
+ * setting non-present entries, or re-setting an existing entry to the
+ * same value. Otherwise, use the typical "set" helpers and flush the
+ * TLB.
+ */
+#define set_pte_safe(ptep, pte) \
+({ \
+	WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \
+	set_pte(ptep, pte); \
+})
+
+#define set_pmd_safe(pmdp, pmd) \
+({ \
+	WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \
+	set_pmd(pmdp, pmd); \
+})
+
+#define set_pud_safe(pudp, pud) \
+({ \
+	WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \
+	set_pud(pudp, pud); \
+})
+
+#define set_p4d_safe(p4dp, p4d) \
+({ \
+	WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \
+	set_p4d(p4dp, p4d); \
+})
+
+#define set_pgd_safe(pgdp, pgd) \
+({ \
+	WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \
+	set_pgd(pgdp, pgd); \
+})
+
+#ifndef __HAVE_ARCH_DO_SWAP_PAGE
+/*
+ * Some architectures support metadata associated with a page. When a
+ * page is being swapped out, this metadata must be saved so it can be
+ * restored when the page is swapped back in. SPARC M7 and newer
+ * processors support an ADI (Application Data Integrity) tag for the
+ * page as metadata for the page. arch_do_swap_page() can restore this
+ * metadata when a page is swapped back in.
+ */
+static inline void arch_do_swap_page(struct mm_struct *mm,
+				     struct vm_area_struct *vma,
+				     unsigned long addr,
+				     pte_t pte, pte_t oldpte)
+{
+
+}
+#endif
+
+#ifndef __HAVE_ARCH_UNMAP_ONE
+/*
+ * Some architectures support metadata associated with a page. When a
+ * page is being swapped out, this metadata must be saved so it can be
+ * restored when the page is swapped back in. SPARC M7 and newer
+ * processors support an ADI (Application Data Integrity) tag for the
+ * page as metadata for the page. arch_unmap_one() can save this
+ * metadata on a swap-out of a page.
+ */
+static inline int arch_unmap_one(struct mm_struct *mm,
+				  struct vm_area_struct *vma,
+				  unsigned long addr,
+				  pte_t orig_pte)
+{
+	return 0;
+}
+#endif
+
+#ifndef __HAVE_ARCH_PGD_OFFSET_GATE
+#define pgd_offset_gate(mm, addr)	pgd_offset(mm, addr)
+#endif
+
+#ifndef __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr)	(pte)
+#endif
+
+#ifndef pte_accessible
+# define pte_accessible(mm, pte)	((void)(pte), 1)
+#endif
+
+#ifndef flush_tlb_fix_spurious_fault
+#define flush_tlb_fix_spurious_fault(vma, address) flush_tlb_page(vma, address)
+#endif
+
+#ifndef pgprot_nx
+#define pgprot_nx(prot)	(prot)
+#endif
+
+#ifndef pgprot_noncached
+#define pgprot_noncached(prot)	(prot)
+#endif
+
+#ifndef pgprot_writecombine
+#define pgprot_writecombine pgprot_noncached
+#endif
+
+#ifndef pgprot_writethrough
+#define pgprot_writethrough pgprot_noncached
+#endif
+
+#ifndef pgprot_device
+#define pgprot_device pgprot_noncached
+#endif
+
+#ifndef pgprot_modify
+#define pgprot_modify pgprot_modify
+static inline pgprot_t pgprot_modify(pgprot_t oldprot, pgprot_t newprot)
+{
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_noncached(oldprot)))
+		newprot = pgprot_noncached(newprot);
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_writecombine(oldprot)))
+		newprot = pgprot_writecombine(newprot);
+	if (pgprot_val(oldprot) == pgprot_val(pgprot_device(oldprot)))
+		newprot = pgprot_device(newprot);
+	return newprot;
+}
+#endif
+
+/*
+ * When walking page tables, get the address of the next boundary,
+ * or the end address of the range if that comes earlier.  Although no
+ * vma end wraps to 0, rounded up __boundary may wrap to 0 throughout.
+ */
+
+#define pgd_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PGDIR_SIZE) & PGDIR_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+
+#ifndef p4d_addr_end
+#define p4d_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + P4D_SIZE) & P4D_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+#endif
+
+#ifndef pud_addr_end
+#define pud_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PUD_SIZE) & PUD_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+#endif
+
+#ifndef pmd_addr_end
+#define pmd_addr_end(addr, end)						\
+({	unsigned long __boundary = ((addr) + PMD_SIZE) & PMD_MASK;	\
+	(__boundary - 1 < (end) - 1)? __boundary: (end);		\
+})
+#endif
+
+/*
+ * When walking page tables, we usually want to skip any p?d_none entries;
+ * and any p?d_bad entries - reporting the error before resetting to none.
+ * Do the tests inline, but report and clear the bad entry in mm/memory.c.
+ */
+void pgd_clear_bad(pgd_t *);
+
+#ifndef __PAGETABLE_P4D_FOLDED
+void p4d_clear_bad(p4d_t *);
+#else
+#define p4d_clear_bad(p4d)        do { } while (0)
+#endif
+
+#ifndef __PAGETABLE_PUD_FOLDED
+void pud_clear_bad(pud_t *);
+#else
+#define pud_clear_bad(p4d)        do { } while (0)
+#endif
+
+void pmd_clear_bad(pmd_t *);
+
+static inline int pgd_none_or_clear_bad(pgd_t *pgd)
+{
+	if (pgd_none(*pgd))
+		return 1;
+	if (unlikely(pgd_bad(*pgd))) {
+		pgd_clear_bad(pgd);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int p4d_none_or_clear_bad(p4d_t *p4d)
+{
+	if (p4d_none(*p4d))
+		return 1;
+	if (unlikely(p4d_bad(*p4d))) {
+		p4d_clear_bad(p4d);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pud_none_or_clear_bad(pud_t *pud)
+{
+	if (pud_none(*pud))
+		return 1;
+	if (unlikely(pud_bad(*pud))) {
+		pud_clear_bad(pud);
+		return 1;
+	}
+	return 0;
+}
+
+static inline int pmd_none_or_clear_bad(pmd_t *pmd)
+{
+	if (pmd_none(*pmd))
+		return 1;
+	if (unlikely(pmd_bad(*pmd))) {
+		pmd_clear_bad(pmd);
+		return 1;
+	}
+	return 0;
+}
+
+static inline pte_t __ptep_modify_prot_start(struct vm_area_struct *vma,
+					     unsigned long addr,
+					     pte_t *ptep)
+{
+	/*
+	 * Get the current pte state, but zero it out to make it
+	 * non-present, preventing the hardware from asynchronously
+	 * updating it.
+	 */
+	return ptep_get_and_clear(vma->vm_mm, addr, ptep);
+}
+
+static inline void __ptep_modify_prot_commit(struct vm_area_struct *vma,
+					     unsigned long addr,
+					     pte_t *ptep, pte_t pte)
+{
+	/*
+	 * The pte is non-present, so there's no hardware state to
+	 * preserve.
+	 */
+	set_pte_at(vma->vm_mm, addr, ptep, pte);
+}
+
+#ifndef __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION
+/*
+ * Start a pte protection read-modify-write transaction, which
+ * protects against asynchronous hardware modifications to the pte.
+ * The intention is not to prevent the hardware from making pte
+ * updates, but to prevent any updates it may make from being lost.
+ *
+ * This does not protect against other software modifications of the
+ * pte; the appropriate pte lock must be held over the transation.
+ *
+ * Note that this interface is intended to be batchable, meaning that
+ * ptep_modify_prot_commit may not actually update the pte, but merely
+ * queue the update to be done at some later time.  The update must be
+ * actually committed before the pte lock is released, however.
+ */
+static inline pte_t ptep_modify_prot_start(struct vm_area_struct *vma,
+					   unsigned long addr,
+					   pte_t *ptep)
+{
+	return __ptep_modify_prot_start(vma, addr, ptep);
+}
+
+/*
+ * Commit an update to a pte, leaving any hardware-controlled bits in
+ * the PTE unmodified.
+ */
+static inline void ptep_modify_prot_commit(struct vm_area_struct *vma,
+					   unsigned long addr,
+					   pte_t *ptep, pte_t old_pte, pte_t pte)
+{
+	__ptep_modify_prot_commit(vma, addr, ptep, pte);
+}
+#endif /* __HAVE_ARCH_PTEP_MODIFY_PROT_TRANSACTION */
+#endif /* CONFIG_MMU */
+
+/*
+ * No-op macros that just return the current protection value. Defined here
+ * because these macros can be used used even if CONFIG_MMU is not defined.
+ */
+#ifndef pgprot_encrypted
+#define pgprot_encrypted(prot)	(prot)
+#endif
+
+#ifndef pgprot_decrypted
+#define pgprot_decrypted(prot)	(prot)
+#endif
+
+/*
+ * A facility to provide lazy MMU batching.  This allows PTE updates and
+ * page invalidations to be delayed until a call to leave lazy MMU mode
+ * is issued.  Some architectures may benefit from doing this, and it is
+ * beneficial for both shadow and direct mode hypervisors, which may batch
+ * the PTE updates which happen during this window.  Note that using this
+ * interface requires that read hazards be removed from the code.  A read
+ * hazard could result in the direct mode hypervisor case, since the actual
+ * write to the page tables may not yet have taken place, so reads though
+ * a raw PTE pointer after it has been modified are not guaranteed to be
+ * up to date.  This mode can only be entered and left under the protection of
+ * the page table locks for all page tables which may be modified.  In the UP
+ * case, this is required so that preemption is disabled, and in the SMP case,
+ * it must synchronize the delayed page table writes properly on other CPUs.
+ */
+#ifndef __HAVE_ARCH_ENTER_LAZY_MMU_MODE
+#define arch_enter_lazy_mmu_mode()	do {} while (0)
+#define arch_leave_lazy_mmu_mode()	do {} while (0)
+#define arch_flush_lazy_mmu_mode()	do {} while (0)
+#endif
+
+/*
+ * A facility to provide batching of the reload of page tables and
+ * other process state with the actual context switch code for
+ * paravirtualized guests.  By convention, only one of the batched
+ * update (lazy) modes (CPU, MMU) should be active at any given time,
+ * entry should never be nested, and entry and exits should always be
+ * paired.  This is for sanity of maintaining and reasoning about the
+ * kernel code.  In this case, the exit (end of the context switch) is
+ * in architecture-specific code, and so doesn't need a generic
+ * definition.
+ */
+#ifndef __HAVE_ARCH_START_CONTEXT_SWITCH
+#define arch_start_context_switch(prev)	do {} while (0)
+#endif
+
+#ifdef CONFIG_HAVE_ARCH_SOFT_DIRTY
+#ifndef CONFIG_ARCH_ENABLE_THP_MIGRATION
+static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline int pmd_swp_soft_dirty(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+#endif
+#else /* !CONFIG_HAVE_ARCH_SOFT_DIRTY */
+static inline int pte_soft_dirty(pte_t pte)
+{
+	return 0;
+}
+
+static inline int pmd_soft_dirty(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline pte_t pte_mksoft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline pmd_t pmd_mksoft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline pte_t pte_clear_soft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline pmd_t pmd_clear_soft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline pte_t pte_swp_mksoft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline int pte_swp_soft_dirty(pte_t pte)
+{
+	return 0;
+}
+
+static inline pte_t pte_swp_clear_soft_dirty(pte_t pte)
+{
+	return pte;
+}
+
+static inline pmd_t pmd_swp_mksoft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+
+static inline int pmd_swp_soft_dirty(pmd_t pmd)
+{
+	return 0;
+}
+
+static inline pmd_t pmd_swp_clear_soft_dirty(pmd_t pmd)
+{
+	return pmd;
+}
+#endif
+
+#ifndef __HAVE_PFNMAP_TRACKING
+/*
+ * Interfaces that can be used by architecture code to keep track of
+ * memory type of pfn mappings specified by the remap_pfn_range,
+ * vmf_insert_pfn.
+ */
+
+/*
+ * track_pfn_remap is called when a _new_ pfn mapping is being established
+ * by remap_pfn_range() for physical range indicated by pfn and size.
+ */
+static inline int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
+				  unsigned long pfn, unsigned long addr,
+				  unsigned long size)
+{
+	return 0;
+}
+
+/*
+ * track_pfn_insert is called when a _new_ single pfn is established
+ * by vmf_insert_pfn().
+ */
+static inline void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
+				    pfn_t pfn)
+{
+}
+
+/*
+ * track_pfn_copy is called when vma that is covering the pfnmap gets
+ * copied through copy_page_range().
+ */
+static inline int track_pfn_copy(struct vm_area_struct *vma)
+{
+	return 0;
+}
+
+/*
+ * untrack_pfn is called while unmapping a pfnmap for a region.
+ * untrack can be called for a specific region indicated by pfn and size or
+ * can be for the entire vma (in which case pfn, size are zero).
+ */
+static inline void untrack_pfn(struct vm_area_struct *vma,
+			       unsigned long pfn, unsigned long size)
+{
+}
+
+/*
+ * untrack_pfn_moved is called while mremapping a pfnmap for a new region.
+ */
+static inline void untrack_pfn_moved(struct vm_area_struct *vma)
+{
+}
+#else
+extern int track_pfn_remap(struct vm_area_struct *vma, pgprot_t *prot,
+			   unsigned long pfn, unsigned long addr,
+			   unsigned long size);
+extern void track_pfn_insert(struct vm_area_struct *vma, pgprot_t *prot,
+			     pfn_t pfn);
+extern int track_pfn_copy(struct vm_area_struct *vma);
+extern void untrack_pfn(struct vm_area_struct *vma, unsigned long pfn,
+			unsigned long size);
+extern void untrack_pfn_moved(struct vm_area_struct *vma);
+#endif
+
+#ifdef __HAVE_COLOR_ZERO_PAGE
+static inline int is_zero_pfn(unsigned long pfn)
+{
+	extern unsigned long zero_pfn;
+	unsigned long offset_from_zero_pfn = pfn - zero_pfn;
+	return offset_from_zero_pfn <= (zero_page_mask >> PAGE_SHIFT);
+}
+
+#define my_zero_pfn(addr)	page_to_pfn(ZERO_PAGE(addr))
+
+#else
+static inline int is_zero_pfn(unsigned long pfn)
+{
+	extern unsigned long zero_pfn;
+	return pfn == zero_pfn;
+}
+
+static inline unsigned long my_zero_pfn(unsigned long addr)
+{
+	extern unsigned long zero_pfn;
+	return zero_pfn;
+}
+#endif
+
+#ifdef CONFIG_MMU
+
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	return 0;
+}
+#ifndef pmd_write
+static inline int pmd_write(pmd_t pmd)
+{
+	BUG();
+	return 0;
+}
+#endif /* pmd_write */
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifndef pud_write
+static inline int pud_write(pud_t pud)
+{
+	BUG();
+	return 0;
+}
+#endif /* pud_write */
+
+#if !defined(CONFIG_ARCH_HAS_PTE_DEVMAP) || !defined(CONFIG_TRANSPARENT_HUGEPAGE)
+static inline int pmd_devmap(pmd_t pmd)
+{
+	return 0;
+}
+static inline int pud_devmap(pud_t pud)
+{
+	return 0;
+}
+static inline int pgd_devmap(pgd_t pgd)
+{
+	return 0;
+}
+#endif
+
+#if !defined(CONFIG_TRANSPARENT_HUGEPAGE) || \
+	(defined(CONFIG_TRANSPARENT_HUGEPAGE) && \
+	 !defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD))
+static inline int pud_trans_huge(pud_t pud)
+{
+	return 0;
+}
+#endif
+
+/* See pmd_none_or_trans_huge_or_clear_bad for discussion. */
+static inline int pud_none_or_trans_huge_or_dev_or_clear_bad(pud_t *pud)
+{
+	pud_t pudval = READ_ONCE(*pud);
+
+	if (pud_none(pudval) || pud_trans_huge(pudval) || pud_devmap(pudval))
+		return 1;
+	if (unlikely(pud_bad(pudval))) {
+		pud_clear_bad(pud);
+		return 1;
+	}
+	return 0;
+}
+
+/* See pmd_trans_unstable for discussion. */
+static inline int pud_trans_unstable(pud_t *pud)
+{
+#if defined(CONFIG_TRANSPARENT_HUGEPAGE) &&			\
+	defined(CONFIG_HAVE_ARCH_TRANSPARENT_HUGEPAGE_PUD)
+	return pud_none_or_trans_huge_or_dev_or_clear_bad(pud);
+#else
+	return 0;
+#endif
+}
+
+#ifndef pmd_read_atomic
+static inline pmd_t pmd_read_atomic(pmd_t *pmdp)
+{
+	/*
+	 * Depend on compiler for an atomic pmd read. NOTE: this is
+	 * only going to work, if the pmdval_t isn't larger than
+	 * an unsigned long.
+	 */
+	return *pmdp;
+}
+#endif
+
+#ifndef arch_needs_pgtable_deposit
+#define arch_needs_pgtable_deposit() (false)
+#endif
+/*
+ * This function is meant to be used by sites walking pagetables with
+ * the mmap_lock held in read mode to protect against MADV_DONTNEED and
+ * transhuge page faults. MADV_DONTNEED can convert a transhuge pmd
+ * into a null pmd and the transhuge page fault can convert a null pmd
+ * into an hugepmd or into a regular pmd (if the hugepage allocation
+ * fails). While holding the mmap_lock in read mode the pmd becomes
+ * stable and stops changing under us only if it's not null and not a
+ * transhuge pmd. When those races occurs and this function makes a
+ * difference vs the standard pmd_none_or_clear_bad, the result is
+ * undefined so behaving like if the pmd was none is safe (because it
+ * can return none anyway). The compiler level barrier() is critically
+ * important to compute the two checks atomically on the same pmdval.
+ *
+ * For 32bit kernels with a 64bit large pmd_t this automatically takes
+ * care of reading the pmd atomically to avoid SMP race conditions
+ * against pmd_populate() when the mmap_lock is hold for reading by the
+ * caller (a special atomic read not done by "gcc" as in the generic
+ * version above, is also needed when THP is disabled because the page
+ * fault can populate the pmd from under us).
+ */
+static inline int pmd_none_or_trans_huge_or_clear_bad(pmd_t *pmd)
+{
+	pmd_t pmdval = pmd_read_atomic(pmd);
+	/*
+	 * The barrier will stabilize the pmdval in a register or on
+	 * the stack so that it will stop changing under the code.
+	 *
+	 * When CONFIG_TRANSPARENT_HUGEPAGE=y on x86 32bit PAE,
+	 * pmd_read_atomic is allowed to return a not atomic pmdval
+	 * (for example pointing to an hugepage that has never been
+	 * mapped in the pmd). The below checks will only care about
+	 * the low part of the pmd with 32bit PAE x86 anyway, with the
+	 * exception of pmd_none(). So the important thing is that if
+	 * the low part of the pmd is found null, the high part will
+	 * be also null or the pmd_none() check below would be
+	 * confused.
+	 */
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	barrier();
+#endif
+	/*
+	 * !pmd_present() checks for pmd migration entries
+	 *
+	 * The complete check uses is_pmd_migration_entry() in linux/swapops.h
+	 * But using that requires moving current function and pmd_trans_unstable()
+	 * to linux/swapops.h to resovle dependency, which is too much code move.
+	 *
+	 * !pmd_present() is equivalent to is_pmd_migration_entry() currently,
+	 * because !pmd_present() pages can only be under migration not swapped
+	 * out.
+	 *
+	 * pmd_none() is preseved for future condition checks on pmd migration
+	 * entries and not confusing with this function name, although it is
+	 * redundant with !pmd_present().
+	 */
+	if (pmd_none(pmdval) || pmd_trans_huge(pmdval) ||
+		(IS_ENABLED(CONFIG_ARCH_ENABLE_THP_MIGRATION) && !pmd_present(pmdval)))
+		return 1;
+	if (unlikely(pmd_bad(pmdval))) {
+		pmd_clear_bad(pmd);
+		return 1;
+	}
+	return 0;
+}
+
+/*
+ * This is a noop if Transparent Hugepage Support is not built into
+ * the kernel. Otherwise it is equivalent to
+ * pmd_none_or_trans_huge_or_clear_bad(), and shall only be called in
+ * places that already verified the pmd is not none and they want to
+ * walk ptes while holding the mmap sem in read mode (write mode don't
+ * need this). If THP is not enabled, the pmd can't go away under the
+ * code even if MADV_DONTNEED runs, but if THP is enabled we need to
+ * run a pmd_trans_unstable before walking the ptes after
+ * split_huge_pmd returns (because it may have run when the pmd become
+ * null, but then a page fault can map in a THP and not a regular page).
+ */
+static inline int pmd_trans_unstable(pmd_t *pmd)
+{
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+	return pmd_none_or_trans_huge_or_clear_bad(pmd);
+#else
+	return 0;
+#endif
+}
+
+#ifndef CONFIG_NUMA_BALANCING
+/*
+ * Technically a PTE can be PROTNONE even when not doing NUMA balancing but
+ * the only case the kernel cares is for NUMA balancing and is only ever set
+ * when the VMA is accessible. For PROT_NONE VMAs, the PTEs are not marked
+ * _PAGE_PROTNONE so by by default, implement the helper as "always no". It
+ * is the responsibility of the caller to distinguish between PROT_NONE
+ * protections and NUMA hinting fault protections.
+ */
+static inline int pte_protnone(pte_t pte)
+{
+	return 0;
+}
+
+static inline int pmd_protnone(pmd_t pmd)
+{
+	return 0;
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+#endif /* CONFIG_MMU */
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+
+#ifndef __PAGETABLE_P4D_FOLDED
+int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot);
+int p4d_clear_huge(p4d_t *p4d);
+#else
+static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int p4d_clear_huge(p4d_t *p4d)
+{
+	return 0;
+}
+#endif /* !__PAGETABLE_P4D_FOLDED */
+
+int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot);
+int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot);
+int pud_clear_huge(pud_t *pud);
+int pmd_clear_huge(pmd_t *pmd);
+int p4d_free_pud_page(p4d_t *p4d, unsigned long addr);
+int pud_free_pmd_page(pud_t *pud, unsigned long addr);
+int pmd_free_pte_page(pmd_t *pmd, unsigned long addr);
+#else	/* !CONFIG_HAVE_ARCH_HUGE_VMAP */
+static inline int p4d_set_huge(p4d_t *p4d, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int pud_set_huge(pud_t *pud, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int pmd_set_huge(pmd_t *pmd, phys_addr_t addr, pgprot_t prot)
+{
+	return 0;
+}
+static inline int p4d_clear_huge(p4d_t *p4d)
+{
+	return 0;
+}
+static inline int pud_clear_huge(pud_t *pud)
+{
+	return 0;
+}
+static inline int pmd_clear_huge(pmd_t *pmd)
+{
+	return 0;
+}
+static inline int p4d_free_pud_page(p4d_t *p4d, unsigned long addr)
+{
+	return 0;
+}
+static inline int pud_free_pmd_page(pud_t *pud, unsigned long addr)
+{
+	return 0;
+}
+static inline int pmd_free_pte_page(pmd_t *pmd, unsigned long addr)
+{
+	return 0;
+}
+#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+#ifndef __HAVE_ARCH_FLUSH_PMD_TLB_RANGE
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+/*
+ * ARCHes with special requirements for evicting THP backing TLB entries can
+ * implement this. Otherwise also, it can help optimize normal TLB flush in
+ * THP regime. stock flush_tlb_range() typically has optimization to nuke the
+ * entire TLB TLB if flush span is greater than a threshold, which will
+ * likely be true for a single huge page. Thus a single thp flush will
+ * invalidate the entire TLB which is not desitable.
+ * e.g. see arch/arc: flush_pmd_tlb_range
+ */
+#define flush_pmd_tlb_range(vma, addr, end)	flush_tlb_range(vma, addr, end)
+#define flush_pud_tlb_range(vma, addr, end)	flush_tlb_range(vma, addr, end)
+#else
+#define flush_pmd_tlb_range(vma, addr, end)	BUILD_BUG()
+#define flush_pud_tlb_range(vma, addr, end)	BUILD_BUG()
+#endif
+#endif
+
+struct file;
+int phys_mem_access_prot_allowed(struct file *file, unsigned long pfn,
+			unsigned long size, pgprot_t *vma_prot);
+
+#ifndef CONFIG_X86_ESPFIX64
+static inline void init_espfix_bsp(void) { }
+#endif
+
+extern void __init pgtable_cache_init(void);
+
+#ifndef __HAVE_ARCH_PFN_MODIFY_ALLOWED
+static inline bool pfn_modify_allowed(unsigned long pfn, pgprot_t prot)
+{
+	return true;
+}
+
+static inline bool arch_has_pfn_modify_check(void)
+{
+	return false;
+}
+#endif /* !_HAVE_ARCH_PFN_MODIFY_ALLOWED */
+
+/*
+ * Architecture PAGE_KERNEL_* fallbacks
+ *
+ * Some architectures don't define certain PAGE_KERNEL_* flags. This is either
+ * because they really don't support them, or the port needs to be updated to
+ * reflect the required functionality. Below are a set of relatively safe
+ * fallbacks, as best effort, which we can count on in lieu of the architectures
+ * not defining them on their own yet.
+ */
+
+#ifndef PAGE_KERNEL_RO
+# define PAGE_KERNEL_RO PAGE_KERNEL
+#endif
+
+#ifndef PAGE_KERNEL_EXEC
+# define PAGE_KERNEL_EXEC PAGE_KERNEL
+#endif
+
+/*
+ * Page Table Modification bits for pgtbl_mod_mask.
+ *
+ * These are used by the p?d_alloc_track*() set of functions an in the generic
+ * vmalloc/ioremap code to track at which page-table levels entries have been
+ * modified. Based on that the code can better decide when vmalloc and ioremap
+ * mapping changes need to be synchronized to other page-tables in the system.
+ */
+#define		__PGTBL_PGD_MODIFIED	0
+#define		__PGTBL_P4D_MODIFIED	1
+#define		__PGTBL_PUD_MODIFIED	2
+#define		__PGTBL_PMD_MODIFIED	3
+#define		__PGTBL_PTE_MODIFIED	4
+
+#define		PGTBL_PGD_MODIFIED	BIT(__PGTBL_PGD_MODIFIED)
+#define		PGTBL_P4D_MODIFIED	BIT(__PGTBL_P4D_MODIFIED)
+#define		PGTBL_PUD_MODIFIED	BIT(__PGTBL_PUD_MODIFIED)
+#define		PGTBL_PMD_MODIFIED	BIT(__PGTBL_PMD_MODIFIED)
+#define		PGTBL_PTE_MODIFIED	BIT(__PGTBL_PTE_MODIFIED)
+
+/* Page-Table Modification Mask */
+typedef unsigned int pgtbl_mod_mask;
+
+#endif /* !__ASSEMBLY__ */
+
+#ifndef io_remap_pfn_range
+#define io_remap_pfn_range remap_pfn_range
+#endif
+
+#ifndef has_transparent_hugepage
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+#define has_transparent_hugepage() 1
+#else
+#define has_transparent_hugepage() 0
+#endif
+#endif
+
+/*
+ * On some architectures it depends on the mm if the p4d/pud or pmd
+ * layer of the page table hierarchy is folded or not.
+ */
+#ifndef mm_p4d_folded
+#define mm_p4d_folded(mm)	__is_defined(__PAGETABLE_P4D_FOLDED)
+#endif
+
+#ifndef mm_pud_folded
+#define mm_pud_folded(mm)	__is_defined(__PAGETABLE_PUD_FOLDED)
+#endif
+
+#ifndef mm_pmd_folded
+#define mm_pmd_folded(mm)	__is_defined(__PAGETABLE_PMD_FOLDED)
+#endif
+
+/*
+ * p?d_leaf() - true if this entry is a final mapping to a physical address.
+ * This differs from p?d_huge() by the fact that they are always available (if
+ * the architecture supports large pages at the appropriate level) even
+ * if CONFIG_HUGETLB_PAGE is not defined.
+ * Only meaningful when called on a valid entry.
+ */
+#ifndef pgd_leaf
+#define pgd_leaf(x)	0
+#endif
+#ifndef p4d_leaf
+#define p4d_leaf(x)	0
+#endif
+#ifndef pud_leaf
+#define pud_leaf(x)	0
+#endif
+#ifndef pmd_leaf
+#define pmd_leaf(x)	0
+#endif
+
+#endif /* _LINUX_PGTABLE_H */
diff --git a/include/linux/rmap.h b/include/linux/rmap.h
index 988d176472df..3a6adfa70fb0 100644
--- a/include/linux/rmap.h
+++ b/include/linux/rmap.h
@@ -77,7 +77,7 @@ struct anon_vma {
 struct anon_vma_chain {
 	struct vm_area_struct *vma;
 	struct anon_vma *anon_vma;
-	struct list_head same_vma;   /* locked by mmap_sem & page_table_lock */
+	struct list_head same_vma;   /* locked by mmap_lock & page_table_lock */
 	struct rb_node rb;			/* locked by anon_vma->rwsem */
 	unsigned long rb_subtree_last;
 #ifdef CONFIG_DEBUG_VM_RB
diff --git a/include/linux/sched/debug.h b/include/linux/sched/debug.h
index 95fb9e025247..00c45a0e6abe 100644
--- a/include/linux/sched/debug.h
+++ b/include/linux/sched/debug.h
@@ -30,7 +30,8 @@ extern void show_regs(struct pt_regs *);
  * task), SP is the stack pointer of the first frame that should be shown in the back
  * trace (or NULL if the entire call-chain of the task should be shown).
  */
-extern void show_stack(struct task_struct *task, unsigned long *sp);
+extern void show_stack(struct task_struct *task, unsigned long *sp,
+		       const char *loglvl);
 
 extern void sched_show_task(struct task_struct *p);
 
diff --git a/include/linux/sched/mm.h b/include/linux/sched/mm.h
index a132d875d351..480a4d1b7dd8 100644
--- a/include/linux/sched/mm.h
+++ b/include/linux/sched/mm.h
@@ -53,7 +53,7 @@ void mmdrop(struct mm_struct *mm);
 
 /*
  * This has to be called after a get_task_mm()/mmget_not_zero()
- * followed by taking the mmap_sem for writing before modifying the
+ * followed by taking the mmap_lock for writing before modifying the
  * vmas or anything the coredump pretends not to change from under it.
  *
  * It also has to be called when mmgrab() is used in the context of
@@ -61,14 +61,14 @@ void mmdrop(struct mm_struct *mm);
  * the context of the process to run down_write() on that pinned mm.
  *
  * NOTE: find_extend_vma() called from GUP context is the only place
- * that can modify the "mm" (notably the vm_start/end) under mmap_sem
+ * that can modify the "mm" (notably the vm_start/end) under mmap_lock
  * for reading and outside the context of the process, so it is also
- * the only case that holds the mmap_sem for reading that must call
- * this function. Generally if the mmap_sem is hold for reading
+ * the only case that holds the mmap_lock for reading that must call
+ * this function. Generally if the mmap_lock is hold for reading
  * there's no need of this check after get_task_mm()/mmget_not_zero().
  *
  * This function can be obsoleted and the check can be removed, after
- * the coredump code will hold the mmap_sem for writing before
+ * the coredump code will hold the mmap_lock for writing before
  * invoking the ->core_dump methods.
  */
 static inline bool mmget_still_valid(struct mm_struct *mm)
diff --git a/include/linux/uaccess.h b/include/linux/uaccess.h
index 9861c89f93be..dac1db05bf7e 100644
--- a/include/linux/uaccess.h
+++ b/include/linux/uaccess.h
@@ -301,62 +301,20 @@ copy_struct_from_user(void *dst, size_t ksize, const void __user *src,
 	return 0;
 }
 
-/*
- * probe_kernel_read(): safely attempt to read from a location
- * @dst: pointer to the buffer that shall take the data
- * @src: address to read from
- * @size: size of the data chunk
- *
- * Safely read from address @src to the buffer at @dst.  If a kernel fault
- * happens, handle that and return -EFAULT.
- */
-extern long probe_kernel_read(void *dst, const void *src, size_t size);
-extern long probe_kernel_read_strict(void *dst, const void *src, size_t size);
-extern long __probe_kernel_read(void *dst, const void *src, size_t size);
+bool probe_kernel_read_allowed(const void *unsafe_src, size_t size);
 
-/*
- * probe_user_read(): safely attempt to read from a location in user space
- * @dst: pointer to the buffer that shall take the data
- * @src: address to read from
- * @size: size of the data chunk
- *
- * Safely read from address @src to the buffer at @dst.  If a kernel fault
- * happens, handle that and return -EFAULT.
- */
+extern long probe_kernel_read(void *dst, const void *src, size_t size);
 extern long probe_user_read(void *dst, const void __user *src, size_t size);
-extern long __probe_user_read(void *dst, const void __user *src, size_t size);
 
-/*
- * probe_kernel_write(): safely attempt to write to a location
- * @dst: address to write to
- * @src: pointer to the data that shall be written
- * @size: size of the data chunk
- *
- * Safely write to address @dst from the buffer at @src.  If a kernel fault
- * happens, handle that and return -EFAULT.
- */
 extern long notrace probe_kernel_write(void *dst, const void *src, size_t size);
-extern long notrace __probe_kernel_write(void *dst, const void *src, size_t size);
-
-/*
- * probe_user_write(): safely attempt to write to a location in user space
- * @dst: address to write to
- * @src: pointer to the data that shall be written
- * @size: size of the data chunk
- *
- * Safely write to address @dst from the buffer at @src.  If a kernel fault
- * happens, handle that and return -EFAULT.
- */
 extern long notrace probe_user_write(void __user *dst, const void *src, size_t size);
-extern long notrace __probe_user_write(void __user *dst, const void *src, size_t size);
-
-extern long strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
-extern long strncpy_from_unsafe_strict(char *dst, const void *unsafe_addr,
-				       long count);
-extern long __strncpy_from_unsafe(char *dst, const void *unsafe_addr, long count);
-extern long strncpy_from_unsafe_user(char *dst, const void __user *unsafe_addr,
-				     long count);
-extern long strnlen_unsafe_user(const void __user *unsafe_addr, long count);
+
+long strncpy_from_kernel_nofault(char *dst, const void *unsafe_addr,
+		long count);
+
+long strncpy_from_user_nofault(char *dst, const void __user *unsafe_addr,
+		long count);
+long strnlen_user_nofault(const void __user *unsafe_addr, long count);
 
 /**
  * probe_kernel_address(): safely attempt to read from a location