Merge tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux

Pull s390 updates from Vasily Gorbik:

 - Add support for stackleak feature. Also allow specifying
   architecture-specific stackleak poison function to enable faster
   implementation. On s390, the mvc-based implementation helps decrease
   typical overhead from a factor of 3 to just 25%

 - Convert all assembler files to use SYM* style macros, deprecating the
   ENTRY() macro and other annotations. Select ARCH_USE_SYM_ANNOTATIONS

 - Improve KASLR to also randomize module and special amode31 code base
   load addresses

 - Rework decompressor memory tracking to support memory holes and
   improve error handling

 - Add support for protected virtualization AP binding

 - Add support for set_direct_map() calls

 - Implement set_memory_rox() and noexec module_alloc()

 - Remove obsolete overriding of mem*() functions for KASAN

 - Rework kexec/kdump to avoid using nodat_stack to call purgatory

 - Convert the rest of the s390 code to use flexible-array member
   instead of a zero-length array

 - Clean up uaccess inline asm

 - Enable ARCH_HAS_MEMBARRIER_SYNC_CORE

 - Convert to using CONFIG_FUNCTION_ALIGNMENT and enable
   DEBUG_FORCE_FUNCTION_ALIGN_64B

 - Resolve last_break in userspace fault reports

 - Simplify one-level sysctl registration

 - Clean up branch prediction handling

 - Rework CPU counter facility to retrieve available counter sets just
   once

 - Other various small fixes and improvements all over the code

* tag 's390-6.4-1' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (118 commits)
  s390/stackleak: provide fast __stackleak_poison() implementation
  stackleak: allow to specify arch specific stackleak poison function
  s390: select ARCH_USE_SYM_ANNOTATIONS
  s390/mm: use VM_FLUSH_RESET_PERMS in module_alloc()
  s390: wire up memfd_secret system call
  s390/mm: enable ARCH_HAS_SET_DIRECT_MAP
  s390/mm: use BIT macro to generate SET_MEMORY bit masks
  s390/relocate_kernel: adjust indentation
  s390/relocate_kernel: use SYM* macros instead of ENTRY(), etc.
  s390/entry: use SYM* macros instead of ENTRY(), etc.
  s390/purgatory: use SYM* macros instead of ENTRY(), etc.
  s390/kprobes: use SYM* macros instead of ENTRY(), etc.
  s390/reipl: use SYM* macros instead of ENTRY(), etc.
  s390/head64: use SYM* macros instead of ENTRY(), etc.
  s390/earlypgm: use SYM* macros instead of ENTRY(), etc.
  s390/mcount: use SYM* macros instead of ENTRY(), etc.
  s390/crc32le: use SYM* macros instead of ENTRY(), etc.
  s390/crc32be: use SYM* macros instead of ENTRY(), etc.
  s390/crypto,chacha: use SYM* macros instead of ENTRY(), etc.
  s390/amode31: use SYM* macros instead of ENTRY(), etc.
  ...

1 files changed, 25 insertions, 4 deletions

diff --git a/arch/s390/kernel/module.c b/arch/s390/kernel/module.c
index b9dbf0c483ed..f1b35dcdf3eb 100644
--- a/arch/s390/kernel/module.c
+++ b/arch/s390/kernel/module.c
@@ -26,6 +26,7 @@
 #include <asm/facility.h>
 #include <asm/ftrace.lds.h>
 #include <asm/set_memory.h>
+#include <asm/setup.h>
 
 #if 0
 #define DEBUGP printk
@@ -35,6 +36,24 @@
 
 #define PLT_ENTRY_SIZE 22
 
+static unsigned long get_module_load_offset(void)
+{
+	static DEFINE_MUTEX(module_kaslr_mutex);
+	static unsigned long module_load_offset;
+
+	if (!kaslr_enabled())
+		return 0;
+	/*
+	 * Calculate the module_load_offset the first time this code
+	 * is called. Once calculated it stays the same until reboot.
+	 */
+	mutex_lock(&module_kaslr_mutex);
+	if (!module_load_offset)
+		module_load_offset = get_random_u32_inclusive(1, 1024) * PAGE_SIZE;
+	mutex_unlock(&module_kaslr_mutex);
+	return module_load_offset;
+}
+
 void *module_alloc(unsigned long size)
 {
 	gfp_t gfp_mask = GFP_KERNEL;
@@ -42,9 +61,11 @@ void *module_alloc(unsigned long size)
 
 	if (PAGE_ALIGN(size) > MODULES_LEN)
 		return NULL;
-	p = __vmalloc_node_range(size, MODULE_ALIGN, MODULES_VADDR, MODULES_END,
-				 gfp_mask, PAGE_KERNEL_EXEC, VM_DEFER_KMEMLEAK, NUMA_NO_NODE,
-				 __builtin_return_address(0));
+	p = __vmalloc_node_range(size, MODULE_ALIGN,
+				 MODULES_VADDR + get_module_load_offset(),
+				 MODULES_END, gfp_mask, PAGE_KERNEL,
+				 VM_FLUSH_RESET_PERMS | VM_DEFER_KMEMLEAK,
+				 NUMA_NO_NODE, __builtin_return_address(0));
 	if (p && (kasan_alloc_module_shadow(p, size, gfp_mask) < 0)) {
 		vfree(p);
 		return NULL;
@@ -491,7 +512,7 @@ static int module_alloc_ftrace_hotpatch_trampolines(struct module *me,
 	start = module_alloc(numpages * PAGE_SIZE);
 	if (!start)
 		return -ENOMEM;
-	set_memory_ro((unsigned long)start, numpages);
+	set_memory_rox((unsigned long)start, numpages);
 	end = start + size;
 
 	me->arch.trampolines_start = (struct ftrace_hotpatch_trampoline *)start;