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
  ...

1 files changed, 11 insertions, 11 deletions

diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c
index c5437f2964ee..0b03ae8c39cd 100644
--- a/arch/x86/mm/fault.c
+++ b/arch/x86/mm/fault.c
@@ -811,7 +811,7 @@ __bad_area(struct pt_regs *regs, unsigned long error_code,
 	 * Something tried to access memory that isn't in our memory map..
 	 * Fix it, but check if it's kernel or user first..
 	 */
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 
 	__bad_area_nosemaphore(regs, error_code, address, pkey, si_code);
 }
@@ -865,7 +865,7 @@ bad_area_access_error(struct pt_regs *regs, unsigned long error_code,
 		 * 2. T1   : set PKRU to deny access to pkey=4, touches page
 		 * 3. T1   : faults...
 		 * 4.    T2: mprotect_key(foo, PAGE_SIZE, pkey=5);
-		 * 5. T1   : enters fault handler, takes mmap_sem, etc...
+		 * 5. T1   : enters fault handler, takes mmap_lock, etc...
 		 * 6. T1   : reaches here, sees vma_pkey(vma)=5, when we really
 		 *	     faulted on a pte with its pkey=4.
 		 */
@@ -1231,15 +1231,15 @@ void do_user_addr_fault(struct pt_regs *regs,
 	 * Kernel-mode access to the user address space should only occur
 	 * on well-defined single instructions listed in the exception
 	 * tables.  But, an erroneous kernel fault occurring outside one of
-	 * those areas which also holds mmap_sem might deadlock attempting
+	 * those areas which also holds mmap_lock might deadlock attempting
 	 * to validate the fault against the address space.
 	 *
 	 * Only do the expensive exception table search when we might be at
 	 * risk of a deadlock.  This happens if we
-	 * 1. Failed to acquire mmap_sem, and
+	 * 1. Failed to acquire mmap_lock, and
 	 * 2. The access did not originate in userspace.
 	 */
-	if (unlikely(!down_read_trylock(&mm->mmap_sem))) {
+	if (unlikely(!mmap_read_trylock(mm))) {
 		if (!user_mode(regs) && !search_exception_tables(regs->ip)) {
 			/*
 			 * Fault from code in kernel from
@@ -1249,7 +1249,7 @@ void do_user_addr_fault(struct pt_regs *regs,
 			return;
 		}
 retry:
-		down_read(&mm->mmap_sem);
+		mmap_read_lock(mm);
 	} else {
 		/*
 		 * The above down_read_trylock() might have succeeded in
@@ -1289,9 +1289,9 @@ good_area:
 	 * If for any reason at all we couldn't handle the fault,
 	 * make sure we exit gracefully rather than endlessly redo
 	 * the fault.  Since we never set FAULT_FLAG_RETRY_NOWAIT, if
-	 * we get VM_FAULT_RETRY back, the mmap_sem has been unlocked.
+	 * we get VM_FAULT_RETRY back, the mmap_lock has been unlocked.
 	 *
-	 * Note that handle_userfault() may also release and reacquire mmap_sem
+	 * Note that handle_userfault() may also release and reacquire mmap_lock
 	 * (and not return with VM_FAULT_RETRY), when returning to userland to
 	 * repeat the page fault later with a VM_FAULT_NOPAGE retval
 	 * (potentially after handling any pending signal during the return to
@@ -1310,7 +1310,7 @@ good_area:
 	}
 
 	/*
-	 * If we need to retry the mmap_sem has already been released,
+	 * If we need to retry the mmap_lock has already been released,
 	 * and if there is a fatal signal pending there is no guarantee
 	 * that we made any progress. Handle this case first.
 	 */
@@ -1320,7 +1320,7 @@ good_area:
 		goto retry;
 	}
 
-	up_read(&mm->mmap_sem);
+	mmap_read_unlock(mm);
 	if (unlikely(fault & VM_FAULT_ERROR)) {
 		mm_fault_error(regs, hw_error_code, address, fault);
 		return;
@@ -1359,7 +1359,7 @@ dotraplinkage void
 do_page_fault(struct pt_regs *regs, unsigned long hw_error_code,
 		unsigned long address)
 {
-	prefetchw(&current->mm->mmap_sem);
+	prefetchw(&current->mm->mmap_lock);
 	/*
 	 * KVM has two types of events that are, logically, interrupts, but
 	 * are unfortunately delivered using the #PF vector.  These events are