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, 2 insertions, 33 deletions

diff --git a/arch/x86/mm/kaslr.c b/arch/x86/mm/kaslr.c
index dc6182eecefa..fb620fd9dae9 100644
--- a/arch/x86/mm/kaslr.c
+++ b/arch/x86/mm/kaslr.c
@@ -24,9 +24,9 @@
 #include <linux/init.h>
 #include <linux/random.h>
 #include <linux/memblock.h>
+#include <linux/pgtable.h>
 
 #include <asm/pgalloc.h>
-#include <asm/pgtable.h>
 #include <asm/setup.h>
 #include <asm/kaslr.h>
 
@@ -61,15 +61,6 @@ static inline unsigned long get_padding(struct kaslr_memory_region *region)
 	return (region->size_tb << TB_SHIFT);
 }
 
-/*
- * Apply no randomization if KASLR was disabled at boot or if KASAN
- * is enabled. KASAN shadow mappings rely on regions being PGD aligned.
- */
-static inline bool kaslr_memory_enabled(void)
-{
-	return kaslr_enabled() && !IS_ENABLED(CONFIG_KASAN);
-}
-
 /* Initialize base and padding for each memory region randomized with KASLR */
 void __init kernel_randomize_memory(void)
 {
@@ -148,7 +139,7 @@ void __init kernel_randomize_memory(void)
 	}
 }
 
-static void __meminit init_trampoline_pud(void)
+void __meminit init_trampoline_kaslr(void)
 {
 	pud_t *pud_page_tramp, *pud, *pud_tramp;
 	p4d_t *p4d_page_tramp, *p4d, *p4d_tramp;
@@ -189,25 +180,3 @@ static void __meminit init_trampoline_pud(void)
 			__pgd(_KERNPG_TABLE | __pa(pud_page_tramp)));
 	}
 }
-
-/*
- * The real mode trampoline, which is required for bootstrapping CPUs
- * occupies only a small area under the low 1MB.  See reserve_real_mode()
- * for details.
- *
- * If KASLR is disabled the first PGD entry of the direct mapping is copied
- * to map the real mode trampoline.
- *
- * If KASLR is enabled, copy only the PUD which covers the low 1MB
- * area. This limits the randomization granularity to 1GB for both 4-level
- * and 5-level paging.
- */
-void __meminit init_trampoline(void)
-{
-	if (!kaslr_memory_enabled()) {
-		init_trampoline_default();
-		return;
-	}
-
-	init_trampoline_pud();
-}