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 <[email protected]>: (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
  ...

Author: torvalds

Documentation/admin-guide/mm/numa_memory_policy.rst

@@ -364,19 +364,19 @@ follows:
 
 2) for querying the policy, we do not need to take an extra reference on the
    target task's task policy nor vma policies because we always acquire the
-   task's mm's mmap_sem for read during the query.  The set_mempolicy() and
-   mbind() APIs [see below] always acquire the mmap_sem for write when
+   task's mm's mmap_lock for read during the query.  The set_mempolicy() and
+   mbind() APIs [see below] always acquire the mmap_lock for write when
    installing or replacing task or vma policies.  Thus, there is no possibility
    of a task or thread freeing a policy while another task or thread is
    querying it.
 
 3) Page allocation usage of task or vma policy occurs in the fault path where
-   we hold them mmap_sem for read.  Again, because replacing the task or vma
-   policy requires that the mmap_sem be held for write, the policy can't be
+   we hold them mmap_lock for read.  Again, because replacing the task or vma
+   policy requires that the mmap_lock be held for write, the policy can't be
    freed out from under us while we're using it for page allocation.
 
 4) Shared policies require special consideration.  One task can replace a
-   shared memory policy while another task, with a distinct mmap_sem, is
+   shared memory policy while another task, with a distinct mmap_lock, is
    querying or allocating a page based on the policy.  To resolve this
    potential race, the shared policy infrastructure adds an extra reference
    to the shared policy during lookup while holding a spin lock on the shared

Documentation/admin-guide/mm/userfaultfd.rst

@@ -33,7 +33,7 @@ memory ranges) provides two primary functionalities:
 The real advantage of userfaults if compared to regular virtual memory
 management of mremap/mprotect is that the userfaults in all their
 operations never involve heavyweight structures like vmas (in fact the
-``userfaultfd`` runtime load never takes the mmap_sem for writing).
+``userfaultfd`` runtime load never takes the mmap_lock for writing).
 
 Vmas are not suitable for page- (or hugepage) granular fault tracking
 when dealing with virtual address spaces that could span

Documentation/filesystems/locking.rst

@@ -615,7 +615,7 @@ prototypes::
 locking rules:
 
 =============	========	===========================
-ops		mmap_sem	PageLocked(page)
+ops		mmap_lock	PageLocked(page)
 =============	========	===========================
 open:		yes
 close:		yes

Documentation/vm/hmm.rst

@@ -191,15 +191,15 @@ The usage pattern is::
 
  again:
       range.notifier_seq = mmu_interval_read_begin(&interval_sub);
-      down_read(&mm->mmap_sem);
+      mmap_read_lock(mm);
       ret = hmm_range_fault(&range);
       if (ret) {
-          up_read(&mm->mmap_sem);
+          mmap_read_unlock(mm);
           if (ret == -EBUSY)
                  goto again;
           return ret;
       }
-      up_read(&mm->mmap_sem);
+      mmap_read_unlock(mm);
 
       take_lock(driver->update);
       if (mmu_interval_read_retry(&ni, range.notifier_seq) {

Documentation/vm/transhuge.rst

@@ -98,9 +98,9 @@ split_huge_page() or split_huge_pmd() has a cost.
 
 To make pagetable walks huge pmd aware, all you need to do is to call
 pmd_trans_huge() on the pmd returned by pmd_offset. You must hold the
-mmap_sem in read (or write) mode to be sure a huge pmd cannot be
+mmap_lock in read (or write) mode to be sure a huge pmd cannot be
 created from under you by khugepaged (khugepaged collapse_huge_page
-takes the mmap_sem in write mode in addition to the anon_vma lock). If
+takes the mmap_lock in write mode in addition to the anon_vma lock). If
 pmd_trans_huge returns false, you just fallback in the old code
 paths. If instead pmd_trans_huge returns true, you have to take the
 page table lock (pmd_lock()) and re-run pmd_trans_huge. Taking the

arch/alpha/boot/bootp.c

@@ -16,7 +16,6 @@
 
 #include <asm/console.h>
 #include <asm/hwrpb.h>
-#include <asm/pgtable.h>
 #include <asm/io.h>
 
 #include <stdarg.h>

arch/alpha/boot/bootpz.c

@@ -18,7 +18,6 @@
 
 #include <asm/console.h>
 #include <asm/hwrpb.h>
-#include <asm/pgtable.h>
 #include <asm/io.h>
 
 #include <stdarg.h>

arch/alpha/boot/main.c

@@ -14,7 +14,6 @@
 
 #include <asm/console.h>
 #include <asm/hwrpb.h>
-#include <asm/pgtable.h>
 
 #include <stdarg.h>
 

arch/alpha/include/asm/io.h

@@ -7,7 +7,6 @@
 #include <linux/kernel.h>
 #include <linux/mm.h>
 #include <asm/compiler.h>
-#include <asm/pgtable.h>
 #include <asm/machvec.h>
 #include <asm/hwrpb.h>
 

arch/alpha/include/asm/pgtable.h

@@ -276,15 +276,6 @@ extern inline pte_t pte_mkwrite(pte_t pte)	{ pte_val(pte) &= ~_PAGE_FOW; return
 extern inline pte_t pte_mkdirty(pte_t pte)	{ pte_val(pte) |= __DIRTY_BITS; return pte; }
 extern inline pte_t pte_mkyoung(pte_t pte)	{ pte_val(pte) |= __ACCESS_BITS; return pte; }
 
-#define PAGE_DIR_OFFSET(tsk,address) pgd_offset((tsk),(address))
-
-/* to find an entry in a kernel page-table-directory */
-#define pgd_offset_k(address) pgd_offset(&init_mm, (address))
-
-/* to find an entry in a page-table-directory. */
-#define pgd_index(address)	(((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1))
-#define pgd_offset(mm, address)	((mm)->pgd+pgd_index(address))
-
 /*
  * The smp_read_barrier_depends() in the following functions are required to
  * order the load of *dir (the pointer in the top level page table) with any
@@ -305,6 +296,7 @@ extern inline pmd_t * pmd_offset(pud_t * dir, unsigned long address)
 	smp_read_barrier_depends(); /* see above */
 	return ret;
 }
+#define pmd_offset pmd_offset
 
 /* Find an entry in the third-level page table.. */
 extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
@@ -314,9 +306,7 @@ extern inline pte_t * pte_offset_kernel(pmd_t * dir, unsigned long address)
 	smp_read_barrier_depends(); /* see above */
 	return ret;
 }
-
-#define pte_offset_map(dir,addr)	pte_offset_kernel((dir),(addr))
-#define pte_unmap(pte)			do { } while (0)
+#define pte_offset_kernel pte_offset_kernel
 
 extern pgd_t swapper_pg_dir[1024];
 
@@ -355,8 +345,6 @@ extern inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
 
 extern void paging_init(void);
 
-#include <asm-generic/pgtable.h>
-
 /* We have our own get_unmapped_area to cope with ADDR_LIMIT_32BIT.  */
 #define HAVE_ARCH_UNMAPPED_AREA